Check Your Brake Caliper for Binding

peteco · 04-03-2020, 09:54 PM

I recently checked the front brakes and caliper sliding action on my 2006 Chevy Roadtrek 210. The calipers slid or moved with great resistance. Upon disassembly it looked like the rubber pin bushings had swelled excessively and the grease was quite "gummy", which prevented the caliper from sliding freely. When I had lubed my slide pins in in 2015 I had used Permatex 24110 Ultra Disc Brake Caliper Lube.

So I just did a quick search and others have had the same issue, and the Permatex is the culprit. The Permatex Ultra Disc Brake Caliper Lube is petroleum based and thus is not suitable for rubber parts. Several Amazon reviewers and others (BITOG) have had the same problem. I don't know why Permatex sells this lube since it apparently is petroleum based, which is known to swell rubber.

https://www.amazon.com/Permatex-2411...cm_cr_arp_d_pr oduct_top?ie=UTF8

Further research shows that silicone brake caliper lube is what is recommended.

I also found that 3 of the major brake parts manufacturers (ACDelco, Raybestos, Carlson) replacement bushings and rubber bellows are made in China. I could not find a made in US part. Based on past experience I would assume the Chinese part material is not as good as the original (assuming US parts), so it is even more important to check your brake caliper sliding performance.

After replacing the pin bushings the brakes seemed to work a bit better. I could also tell the difference at a stop when I took my foot off the brake pedal. THe vehicle creeps along at idle faster than before the brake caliper service.

booster · 04-03-2020, 11:21 PM

Pete had let me know about this a bit earlier, so I had a chance to check our Chevy van and our 09 CRV as both had been cleaned and lubed within the last year with Raybestos High Temperature Synthetic Brake Grease, which is probably similar to the Pematex product Pete used. I just finished checking both our vehicles.

Ours showed the same swelling and softening as Pete's did in the van, although only the front was somewhat stuck. It was very hard to get the swelled, mushy, pin sleeve out of the blind bore of adapter because it had no integrity to hook and pull on with hook and just tore. The rears weren't stuck and likely wouldn't ever be from this issue as the boots are all external so no swelling against the pins, and there are no bore sleeves of rubber. The boots were swelled enough to let in water and dirt to pins and bores, though.

The CRV had similar a front system and was also stuck, with the same swelling. The rears, however, were not stock but didn't have the internal sleeves. The boots were not swollen at all even though they were covered with grease. Of note was that the replacement parts were identical Raybestos parts from the same vendor as what I had put in a year ago and the rears came in older style packaging than the fronts, so that might indicate a material change in the time to move the stock. Both packing styles were from China, however.

I tried to find the rubber specification for as many brands as I could for their rubber brake slide parts and found it very hard to find. What I did find all indicated that they are made of EPDM which is rated as incompatible with petroleum grease, so the problem is totally understandable with EPDM parts. Nitrile, which I think is what these parts have been traditionally made of, based on past appearance, smell, and feel, is rated as compatible with the petroleum grease, so that makes it understandable that the decades of use of the petroleum based brake greases didn't show up a problem. EPDM has a somewhat better heat tolerance, so maybe that is why they probably switched material, but it also could be a Nitrile availability and quality out of China being an issue. At a previous job they moved a specialty nitrile product from the US to China and we could not get acceptable quality from them, but it wasn't a swelling issue.

For those of use that have used the same greases for decades without issue, this is quite a wake up call. Thanks go to Pete for identifying the issue, doing the legwork of research, and getting information on the now recommended grease, which is Sil-glyde silicone based grease which has been around for a long, long, time, but mostly used to lube and seal spark plug boots and other electrical stuff, I think.

It is always a good idea to check how well the slides are working yearly if you do your own work as they do stick often, especially in salted road areas of the country.

jmai · 04-04-2020, 01:01 AM

In general, its pretty standard that you don't use petroleum based greases on rubber components because of the swelling. If you have to lube a rubber part or O ring, silicone grease is fine. Otherwise, just lube it with the fluid it will be sealing, such as brake fluid for master cylinder or wheel cylinder seals and motor oil for filters and engine seals.

If you want to do a quick check of your brakes, remove the wheel and look at the inspection hole in the brake caliper and look at your brake pads. On each side of the rotor you will see the pad. Ideally, they both should be the same thickness. If one is substantially more worn than the other, you may have gummy guide pins and swollen rubber as described in the original post. A sticking brake piston can also cause a pad imbalance.

Servicing one's brakes involves more than changing the pads. One should also check the guide pins, rubber guide boots or covers, lubrication for the sliding parts of the caliper and brake pad ears and brake quiet or shims for the back of the pads. In addition, rubber brake hoses should be checked (look for swelling) and also torque bolts to factory specs. In addition, brakes should be bled every 2 years or so to be safe and insure that your brake fluid is water free and your brake pedal has a solid feel so they can be modulated when you press the pedal.

booster · 04-04-2020, 02:46 AM

Quote:

Originally Posted by jmai

In general, its pretty standard that you don't use petroleum based greases on rubber components because of the swelling. If you have to lube a rubber part or O ring, silicone grease is fine. Otherwise, just lube it with the fluid it will be sealing, such as brake fluid for master cylinder or wheel cylinder seals and motor oil for filters and engine seals.

If you want to do a quick check of your brakes, remove the wheel and look at the inspection hole in the brake caliper and look at your brake pads. On each side of the rotor you will see the pad. Ideally, they both should be the same thickness. If one is substantially more worn than the other, you may have gummy guide pins and swollen rubber as described in the original post. A sticking brake piston can also cause a pad imbalance.

Servicing one's brakes involves more than changing the pads. One should also check the guide pins, rubber guide boots or covers, lubrication for the sliding parts of the caliper and brake pad ears and brake quiet or shims for the back of the pads. In addition, rubber brake hoses should be checked (look for swelling) and also torque bolts to factory specs. In addition, brakes should be bled every 2 years or so to be safe and insure that your brake fluid is water free and your brake pedal has a solid feel so they can be modulated when you press the pedal.

I would have to disagree with the statement that rubber compounds don't like petroleum products. I would point out all the seals in an engine, trans, differential, wheel bearings, etc etc. plus tons of industrial products. The deal is that some compounds swell in petroleum oils and greases and epdm is one of them. Nitrile, as I mentioned in my post as the likely older compound is fine, so is viton but more expensive and less versatile.

The application in the brakes in in the non wetted parts so brake fluid would not be used for it as it would not survive the conditions and is a poor lubricant. The brake grease mentioned by Pete and in my post have both been recommended for bushings and slides for decades and worked well until now. Permatex may still be recommending them, and so may Raybestos and that is why this post is so important, IMO. The brake grease itself is still useful in the brake assemblies as it is a high temp product with moly so much better than silicone for the sliding parts like the pad guides, backs of pads to pistons and adapters, etc. I used both the grease and Silglyde when I reassembled ours the last couple of days. It will be interesting to me to see how well the Silglyde holds up over time in the heat and high unit loading it will see. Normally, I would expect a moly grease (no good any more) or a teflon added product for low speed/high load metal to metal application (they go metal to metal under braking as the rubber compresses, the rears of the van are metal to metal all the time). Not a usual silicone grease application in my experience.

All you have to do is read the vehicle forums and Bob is the oil Guy to see just how many people had been using the greases for years until all of a sudden it didn't work anymore, including me and most of the DIY mechanics I know. I would guess that there are lots of vehicles out there with stuck calipers because of this issue, depending on how quickly the news traveled through the local shop information mill. Folks like the Snap-on traveling tool truck rep are great carriers of new information, besides selling excellent but very expensive tools, so the news may have been spread quickly before too many vehicles got out. I sure hope so.

jmai · 04-04-2020, 03:41 PM

Quote:

Originally Posted by booster

I would have to disagree with the statement that rubber compounds don't like petroleum products. I would point out all the seals in an engine, trans, differential, wheel bearings, etc etc. plus tons of industrial products. The deal is that some compounds swell in petroleum oils and greases and epdm is one of them. Nitrile, as I mentioned in my post as the likely older compound is fine, so is viton but more expensive and less versatile.

The application in the brakes in in the non wetted parts so brake fluid would not be used for it as it would not survive the conditions and is a poor lubricant. The brake grease mentioned by Pete and in my post have both been recommended for bushings and slides for decades and worked well until now. Permatex may still be recommending them, and so may Raybestos and that is why this post is so important, IMO. The brake grease itself is still useful in the brake assemblies as it is a high temp product with moly so much better than silicone for the sliding parts like the pad guides, backs of pads to pistons and adapters, etc. I used both the grease and Silglyde when I reassembled ours the last couple of days. It will be interesting to me to see how well the Silglyde holds up over time in the heat and high unit loading it will see. Normally, I would expect a moly grease (no good any more) or a teflon added product for low speed/high load metal to metal application (they go metal to metal under braking as the rubber compresses, the rears of the van are metal to metal all the time). Not a usual silicone grease application in my experience.

All you have to do is read the vehicle forums and Bob is the oil Guy to see just how many people had been using the greases for years until all of a sudden it didn't work anymore, including me and most of the DIY mechanics I know. I would guess that there are lots of vehicles out there with stuck calipers because of this issue, depending on how quickly the news traveled through the local shop information mill. Folks like the Snap-on traveling tool truck rep are great carriers of new information, besides selling excellent but very expensive tools, so the news may have been spread quickly before too many vehicles got out. I sure hope so.

Rubber and petroleum grease:

Some clarification, actual rubber is not compatible with petroleum grease, whereas other rubber compounds, such as, nitrile and vitron are compatible. Unfortunately, in this day and age of aftermarket parts and Chinese parts. it can be hard to determine the actual material of a seal or O ring. when in doubt, I apply a bit of silicone.

Silicone grease vs moly grease:

Silicone grease is not a substitute for moly grease. However is is the recommended grease for disc brakes, but not drum brakes. Over the past 15 years I have been using silicone based grease when I service my disc brakes. It has held up with no problem. It will tolerate the high heat from brake rotors and brake pads. I have purchased brake grease made by Volvo and Ate (major brake manufacturer) and they have all been silicone based and tolerable for high heat. I have also used Syn-glide, available from NAPA.

I recently put new calipers, pads and rotors on the front of my 2001 Dodge Roadktrek 190 Popular. I used silicone grease on the components. Three months later, I drove from Massachusetts to North Carolina and back and spent many miles on the hills of the Blue Ridge Parkway. The brakes got a good workout and performed well. I have also used the silicone grease on my sports cars and daily drivers and had no problems.

For rear drum brakes, a moly based grease is recommended where the brake shoes contact the backing plate and at various pivot points for the brake shoes and emergency brake components.

As a DIY home mechanic, I try to be diligent. I can afford to spend the time researching the best procedure and recommended lubricants and that is what I try to do.

booster · 04-04-2020, 04:56 PM

Not arguing semantics, but the whole point of this thread was to point out that there has been a change of products over time, and that the grease manufacturers and suppliers of the elastomer products that are not compatible with petroleum greases kept selling grease that destroyed their own products. It took several years of complaints to get them to even put disclaimers into place about "use only on metal to metal contact parts" and they still recommend the grease for caliper pins and bushings. No recommended greases or warnings if you buy a "bushing kit" which is almost always the rubber parts so if you read the tube of grease you think you are good to go. To me this is just not what should happen, especially when the parts and grease used to be compatible.

Research is great, good for you catching it early, or maybe your using silicone more than many would saved you, no matter. But if you did research and went to the Raybestos site even a year ago, they would have recommended petroleum grease with no note even about metal to metal so that is what you would have gotten. Several people even called them and Permatex and were told the recommendation was the petroleum grease. They claimed no knowledge of the swelling issues.

IMO, there is really no good reason to make the rubber parts out of EPDM, except maybe cost or difficulty finding vendors for EPDM in the foreign supply chain. The rubber parts of the caliper guide system are of the same design and use as steering components like ball joints rather than brake parts as the see lots of stuff that wetted brake parts don't, like grease. Perhaps the reason is as simple as brake companies deal mostly in metal parts and friction materials, or wetted parts, so a non wetted elastomer part would just be easier to make out of the same materials.

You can determine the type of elastomer to a large degree by doing a burn test on it, but it costs you a part.

Quote:

Burning Test of various elastomers. Nitrile (NBR): It burns with a sooty flame leaving an untolerable smell. EPDM: Burns readily with a sooty flame leaving a dry & waxy odour. BUTYL (IIR): Burns readily with a phenolic odour and if colour tested with Pyrolysate, it will give a positive test.

An interesting thing that was pointed out somewhere that I saw recently was that Silglyde actually has very little silicone in it compared to "true" silicone greases. They had a copy of a no longer posted by Silglyde MSDS that showed the % of the materials to confirm it. IIRC it was some versions of esters and such.

One thing I certainly would recommend to everyone that hires their repairs done would be to ask what the shop uses for pin grease. Some may take issue with the question, but I do think it is important. I would hope by now most or all would have completely switched away from petroleum greases (I have seen shops use chassis grease or wheel bearing grease also) except for the far from rubber part areas that are high load metal to metal.

peteco · 04-04-2020, 06:12 PM

Just checked the Permatex Ultra Disc Brake Caliper Lube technical data sheet. Here are a few excerpts:

TYPICAL APPLICATIONS
• Long and short bolts
• Outboard pad backing plate
• Inboard pad backing plate
• Disc brake calipers
• Caliper pins
• Pistons

Non-silicone, non-petroleum based formula
Pure synthetic lubricant, environmentally safe

If it is "non-petroleum" then there is something in it that causes swelling. ALso note that it says it can be used on caliper pins.

https://441py33rout1ptjxn2lupv31-wpe.../tds/24110.pdf

On the Permatex main information page it says:

For metal-to-metal contact only.

So I guess they expect the user to look at both and figure out it is OK for metal on metal caliper pins/housings, but not if there are rubber sleeves.

https://www.permatex.com/products/lu...aliper-lube-4/

My older can of the Permatex Ultra does not have the "For metal-to-metal contact only" warning.

I assume Permatex knows this product causes swelling. I wonder why Permatex has not pulled this product from the market, as many will probably continue to use it on caliper pins, as they don't know if there are sleeves or just metal to metal contact.

I wonder also how much the problem is due to material changes over the years.

Regardless, from now on I will only use Silicone grease made specifically for brakes. And I will check the brakes more frequently for proper caliper movement.

https://www.amazon.com/Raybestos-DBL.../dp/B0015RCGRM

https://www.amazon.com/3M-08946-Clea...omotive&sr=1-1

I also wonder if there are other brake lube products that cause swelling like the Permatex; probably so.

booster · 04-04-2020, 06:25 PM

My grease that caused swelling is Raybestos, so them for sure. It also has no disclaimer of metal on metal on the tube.

I would guess lots of grease manufacturers and brake companies have/had similar.

On edit

I just looked at the Bendix site and they have a synthetic grease that the claim is safe for all materials including EPDM and nitrile. The refer to a JIS spec for brake system lubricants that specifically addresses rubber compatibility and likely also mentions EPDM and nitrile. You have to pay to look at the spec all the places I saw, so hard to confirm for sure. It would certainly indicate, based on the Bendix claim that they certainly know that EPDM and nitrile compatibility is needed, so it is very hard to understand how the other manufacturers haven't also known for a long time. It would also indicate to me, based on it being a JIS spec, that it certainly could be that the need for the spec was because the US was primarily nitrile and Japan and likely other countries were EPDM, but that is speculation on my part. When the domestic companies put it offshore, EPDM got top billing I would guess so that is what the used. They did lag with the acceptable lubes, though, as that is very apparent even now.

jmai · 04-04-2020, 07:17 PM

Booster and Peteco

Thanks for the info-very informative

booster · 04-05-2020, 01:51 PM

While only borderline applicable to what we are talking about here, I figured it might be interesting to put up a pic of the absolutely horribly designed 1992 Escort bushings. This setup would be the poster child for caliper slide lockup if the bushings swelled even a tiny amount.

The long bushings went on one of the pins, and two short bushings on the other on each caliper. The long bushing went all the way through the caliper with a bellows on each end and fit tightly on the bore of the hole. The calipers were cast iron. The pins went through the bushing and were retained by the adapter on each end.

I took nearly no time in Minnesota to have the water/salt find it's way into the bore of hole and rust it from both ends. When iron rusts, it expands, so it would tighten the bushing on the pin until it would barely even move with a hammer, much less slide freely. Most of any grease you used would get squeezed out from the pressure of the pin on the bushing so there was nearly none left to prevent the rust. I needed to disassemble and ream the holes out every year. By 1997, when we got DW's basically same car Tracer, the problem was a bit less and I could go two years, but never did out of caution. They had made the bore of hole in the caliper much larger to allow for rust, which would get to a relatively consistent thickness that was allowed for and then slow down further increases. If cleaned up of rust, they were loose enough to allow the caliper to move around, making it noisy on bumps until they rusted again.

peteco · 04-05-2020, 04:47 PM

Quote:

Originally Posted by booster

While only borderline applicable to what we are talking about here, I figured it might be interesting to put up a pic of the absolutely horribly designed 1992 Escort bushings. This setup would be the poster child for caliper slide lockup if the bushings swelled even a tiny amount.

The long bushings went on one of the pins, and two short bushings on the other on each caliper. The long bushing went all the way through the caliper with a bellows on each end and fit tightly on the bore of the hole. The calipers were cast iron. The pins went through the bushing and were retained by the adapter on each end.

I took nearly no time in Minnesota to have the water/salt find it's way into the bore of hole and rust it from both ends. When iron rusts, it expands, so it would tighten the bushing on the pin until it would barely even move with a hammer, much less slide freely. Most of any grease you used would get squeezed out from the pressure of the pin on the bushing so there was nearly none left to prevent the rust. I needed to disassemble and ream the holes out every year. By 1997, when we got DW's basically same car Tracer, the problem was a bit less and I could go two years, but never did out of caution. They had made the bore of hole in the caliper much larger to allow for rust, which would get to a relatively consistent thickness that was allowed for and then slow down further increases. If cleaned up of rust, they were loose enough to allow the caliper to move around, making it noisy on bumps until they rusted again.

Scary design. In December I did front brakes on my daughter-in-law 2006 Honda civic with 120,000 miles. I didn't pay attention to the caliper and pin design, but did note that the caliper slid nice and smooth. The brakes worked well with no noted looseness. So apparently a good design.

The GM design appears ok too, but swelling of bushings is a problem that should be highlighted to be looked at during a brake job, especially by diy folks like us. The scary thing is many brake shops probably don't pay attention to or even know about these details like some of us do, or have discovered.

booster · 04-05-2020, 07:45 PM

Quote:

Originally Posted by peteco

Scary design. In December I did front brakes on my daughter-in-law 2006 Honda civic with 120,000 miles. I didn't pay attention to the caliper and pin design, but did note that the caliper slid nice and smooth. The brakes worked well with no noted looseness. So apparently a good design.

The GM design appears ok too, but swelling of bushings is a problem that should be highlighted to be looked at during a brake job, especially by diy folks like us. The scary thing is many brake shops probably don't pay attention to or even know about these details like some of us do, or have discovered.

The Honda was probably like our CRV, which is very similar to the GM setup. Sleeve on the end of one pin on the front brakes with the other pin with a flat on it. Rear a solid pin and flatted pin. The CRV was also loose after 10 years before the grease fiasco.

Roadtreker357 · 04-10-2020, 03:45 PM

I am glad this subject has come up. I have used the incorrect Permatex lube for the slide pins and now have work to do to redo three vehicles. In my ignorance, I used a lube designed for just metal to metal contact. With virus restrictions, there is time to tackle this remedial action. I just hope no permanent damage has been done, so it is a simple as clean off the old and apply the new.

I ordered to be delivered to my local O'Reilly store a Permatex silicone lube, #80653. This link goes to the product description, where it states it is suitable for EPDM and Nitrile. If you look under Tech Docs, there is a TDS.
https://www.permatex.com/products/lu...rts-lubricant/

If any of you take exception to this being a satisfactory product to use, please give a shout.

peteco · 04-10-2020, 04:00 PM

Quote:

Originally Posted by Roadtreker357

I am glad this subject has come up. I have used the incorrect Permatex lube for the slide pins and now have work to do to redo three vehicles. In my ignorance, I used a lube designed for just metal to metal contact. With virus restrictions, there is time to tackle this remedial action. I just hope no permanent damage has been done, so it is a simple as clean off the old and apply the new.

I ordered to be delivered to my local O'Reilly store a Permatex silicone lube, #80653. This link goes to the product description, where it states it is suitable for EPDM and Nitrile. If you look under Tech Docs, there is a TDS.
https://www.permatex.com/products/lu...rts-lubricant/

If any of you take exception to this being a satisfactory product to use, please give a shout.

The Permatex Silicone Ceramic Extreme is what I am now using. Time will tell if it is good.

Unfortunately you probably need to replace, at a minimum, the rubber pin sleeves inside the caliper. These are what "grab" the slide pin and restrict motion. I used a bolt to thread into the sleeve to pull it out. I think other have used a pick. This may be difficult if the bushings have swelled excessively.

I also replaces the rubber bellows on the outside of the caliper. This turned into a major task as the new bellows were very tight. I damaged a couple of them and had to get more new ones. On some I had to file the metal collar to get them in. I eventually rigged up a long clamp to press the new ones in, but it worked only marginally well. I would figure out a better way to press them in if I have to do it again. So one option is to not replace the bellows. But this makes it harder to clean out the old grease, which must be done to prevent contamination of the new grease.

Another option is to get new calipers. This is not as easy as it once was because many new calipers are made in China and are, in my opinion, of lesser quality than the OEM calipers that came on the vehicle.

Let us know how it goes.

Roadtreker357 · 04-10-2020, 04:07 PM

Thanks for the details Peteco. I appreciate that. Will start on this project next week and report back.

booster · 04-10-2020, 04:07 PM

Quote:

Originally Posted by Roadtreker357

I am glad this subject has come up. I have used the incorrect Permatex lube for the slide pins and now have work to do to redo three vehicles. In my ignorance, I used a lube designed for just metal to metal contact. With virus restrictions, there is time to tackle this remedial action. I just hope no permanent damage has been done, so it is a simple as clean off the old and apply the new.

I ordered to be delivered to my local O'Reilly store a Permatex silicone lube, #80653. This link goes to the product description, where it states it is suitable for EPDM and Nitrile. If you look under Tech Docs, there is a TDS.
https://www.permatex.com/products/lu...rts-lubricant/

If any of you take exception to this being a satisfactory product to use, please give a shout.

I think that lube would be fine, as they seem to have finally wised up to the issue.

I would also say that it is unlikely that you would be able to just clean up what you have and relube if they have seen the wrong grease. The grease is absorbed quite quickly, although the swelling can be delayed by quite a period of time as it travels through the materials. It can be a bunch of work to get the job done, and the bushings are cheap, so I just ordered a new set of the each of the vehicles ahead of time. Rock Auto ships them right to the door so no going out. Personally, I would risk the chance of having to do it all a third time. I think our bushing were between $5-10 per vehicle, so no big deal.

Roadtreker357 · 04-10-2020, 05:59 PM

The "wrong" lube I used is synthetic and says it is for pins. But, it also says it is just for metal to metal contact. I will take a look at one caliper this afternoon.
This is what I used:
https://www.permatex.com/products/lu...s-lubricant-2/

With some luck, maybe it did not ruin the non-metal parts.

peteco · 04-10-2020, 06:09 PM

Quote:

Originally Posted by Roadtreker357

The "wrong" lube I used is synthetic and says it is for pins. But, it also says it is just for metal to metal contact. I will take a look at one caliper this afternoon.
This is what I used:
https://www.permatex.com/products/lu...s-lubricant-2/

With some luck, maybe it did not ruin the non-metal parts.

I would not trust that it did not damage the rubber sleeves, and would replace just to make sure. Take a look at the Amazon reviews. Several had pin seizure problems. Permatex has really bombed on this issue. Makes me leery of using any of their stuff now. I hope the silicone lube is OK. If buying new I think I would get the 3m stuff I listed earlier.

https://www.amazon.com/Permatex-2412...0018PSASU?th=1

booster · 04-10-2020, 06:21 PM

If you have the capability to get the adapters off, as in big wrench and a pipe, those can mounted press in bellows get a lot easier as you can use a vise and socket or hammer and socket. That saves messing the wet parts and lets you get them cleaner. Getting all the old grease out the blind holes in very hard on the vehicle.

It would have been nearly impossible for me to replace the damaged pin sleeves without removing the bellows because the sleeve did not come out with the pin and was severely stuck and gooey at the bottom of the hole. It was very hard to get out.

Do the replacement calipers come with adapters in all cases? It has been decades since I have need to buy one so I don't recall.

peteco · 04-10-2020, 07:02 PM

Quote:

Originally Posted by booster

If you have the capability to get the adapters off, as in big wrench and a pipe, those can mounted press in bellows get a lot easier as you can use a vise and socket or hammer and socket. That saves messing the wet parts and lets you get them cleaner. Getting all the old grease out the blind holes in very hard on the vehicle.

It would have been nearly impossible for me to replace the damaged pin sleeves without removing the bellows because the sleeve did not come out with the pin and was severely stuck and gooey at the bottom of the hole. It was very hard to get out.

Do the replacement calipers come with adapters in all cases? It has been decades since I have need to buy one so I don't recall.

Agree, replacing bellows is best. The "adapter" you refer to; is that the caliper mounting bracket? If so then yes, that is good to remove for another reason also: to lube the wheel bearings. Read the discussion below. This is very important on our heavy Chevy's. There are other discussions on the internet regarding the importance of lubing bearings on the Chevy Silverado, Express, and other GM vehicles that used sealed front bearings. Now is the time to do it when you are in there.

https://www.classbforum.com/forums/f...ings-2305.html

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