Caliper boot repair

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Dec 11, 2019
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Hello, The rear-left caliper boot on my 06 Saab 9-3 2.0T has a big tear and I would really appreciate some feedback on the fluids I'm using for its repair. First, my situation is as follows. I looked up the numbering on the boot and as far as I can tell the boot doesn't go into the bore so I should be able to replace it without caliper disassembly and rebuilding. An example (not mine) image of what my caliper looks like w/o the boot: [Linked Image] The outer circumference of the 'lip' that goes around the piston is where it contacts the boot. When I gently pried up the boot there was a white and yellow hardened residue along this area which looked like an adhesive that was helping stick the bottom of the boot to the metal lip. I slowly scraped off this gunk from the lip w/ a piece of plastic and wiped the area w/ brake cleaner sprayed on a non-lint paper towel. I cleaned the grease off the visible walls of the piston (it was contaminated with dirt) and used a strip of paper to kick out the tiny grains of dirt which were lodged at the really tiny gap between the piston and the bore. I ordered a Dorman D670131 boot repair kit as a replacement which is an OE compatible part. The rubber material is listed as EPDM. Now to my questions. To replace the contaminated grease I cleaned off the piston, I was thinking of using Raybestos BAF12 hydraulic brake assembly fluid (randomly inherited the bottle). Is this ok to use? The bottle says it's a polyalkylene fluid which I'm assuming means it's a polyalkylene glycol? If so I think this should be compatible with EPDM and the DOT 4 in my brake system. I'd prefer not to use DOT 4 since I'd have to buy a new bottle of it just for this and I know it absorbs water over time. For my second question, what is an appropriate replacement adhesive to use for the new EPDM boot? I can't find any of the 3M scotch-weld stuff locally or on amazon (CA). Is it even necessary given the potential for contamination? The entire caliper is very light so I'm assuming the bonding surface is aluminum and not some kind of chrome plated or stainless steel. Thanks
 
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I would either replace the caliper or completely disassemble and rebuild it with a rebuild kit. The piston needs to be inspected for any rust or pitting. Anything Doorman is crap.
 

avalon

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Originally Posted by Donald
I would either replace the caliper or completely disassemble and rebuild it with a rebuild kit. The piston needs to be inspected for any rust or pitting. Anything Doorman is crap.
Thanks for the suggestion, I will consider it. I was replacing the rear pads at the same time and the rear piston on the opposite side was definitely pretty hard to push back in. I haven't had any issues with Dorman but I've heard that about them. The main reason I went with them for this wasn't price but rather fast availability of the part.
 
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Donald, I read and regard your posts and while I'm grateful for a heads up, a blanket condemnation of Dorman's product line seems too broad. Specific brands like Professional Parts Sweden and Cardone are routinely excoriated. We can assume they seek the lowest bids. However, there has always been those parts which are close to or match the originals. They may be dwindling in number and becoming harder to find. I think Dorman is just in the mix, perhaps in the higher half. Their catalog simply doesn't have multiple offerings like RockAuto has so frequently. Or were you just focusing on brake repair kits?
 
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Originally Posted by Kira
Donald, I read and regard your posts and while I'm grateful for a heads up, a blanket condemnation of Dorman's product line seems too broad. Specific brands like Professional Parts Sweden and Cardone are routinely excoriated. We can assume they seek the lowest bids. However, there has always been those parts which are close to or match the originals. They may be dwindling in number and becoming harder to find. I think Dorman is just in the mix, perhaps in the higher half. Their catalog simply doesn't have multiple offerings like RockAuto has so frequently. Or were you just focusing on brake repair kits?
I am not saying everything from Doorman should be avoided but as you say it's a mixed bag. I bought SS lug nuts from Doorman to replace the OEM chrome over steel and they were fine. Other stuff from Doorman was not so good. If the part is easy to swap out them maybe try Doorman. But if hours of work to swap then if it's Doorman or OEM I go with OEM. If there is another manufacturer listed in RA that supplies a part then I most likely go with other company. Sometimes Doorman is the only one listed.
 
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I hear that. Dorman lists a replacement transmission pan with a DRAIN PLUG which I installed on my Ranger (5R55E?). The stamping is truly nice and smooth and the finish seems top shelf. Still I said to myself, "Do they produce these using differing quality levels of steel and did I get a good one?" For a friend I installed a pair of simple folded metal bumper brackets -source unknown. In 3 years they were graham crackers. Another friend bought exhaust manifolds for his '97 F-150. TWO YEARS LATER they had to be replaced. Don't know the name or source but baddies can pop up on any website. Rotten manifolds would burn my you-know-what.
 

JHZR2

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I'd want to at minimum pull the pistons and replace the square cut seal in there. Not a ton of work but can be a bit of a hassle on old dirty calipers.
 

avalon

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Originally Posted by JHZR2
I'd want to at minimum pull the pistons and replace the square cut seal in there. Not a ton of work but can be a bit of a hassle on old dirty calipers.
Thanks for the suggestion. I wonder if there will be any issues as I had read that a DIY rebuild is not really possible (or is very impractical) for these specific (Saab 9-3 rear) calipers due to a 'worm drive' piston. Not yet sure what that means but I will need to look around for some rebuild videos as I've never done it before. I think EricTheCarGuy has a really good one. That and I'll post on a Saab specific forum to get some more guidance.
 
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Saabs have to use a ATE or TRW(Lucas) caliper that's the common pick of European cars - and with some sleuthing between aftermarket part numbers from Dorman or Carlson Brake Parts, you would be able to track down a OEM rebuild kit from another Euro brand that will work. Seals can be lubed up with brake fluid, or DOT fluid compatible grease like Toyota's red rubber grease for brakes or SRAM's DOT grease. Boots go on dry, most of them have a circlip that's massaged into the ID of the boot between the piston and bore to secure it in place. I never tore apart a caliper with an integral parking brake - the hard part would be getting the piston back in and resetting the ratcheting mechanism that works parking brake. If anything, it would be like this guide: https://www.svocop.com/Articles/2/index.html
 

avalon

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Originally Posted by nthach
Saabs have to use a ATE or TRW(Lucas) caliper that's the common pick of European cars - and with some sleuthing between aftermarket part numbers from Dorman or Carlson Brake Parts, you would be able to track down a OEM rebuild kit from another Euro brand that will work. Seals can be lubed up with brake fluid, or DOT fluid compatible grease like Toyota's red rubber grease for brakes or SRAM's DOT grease. Boots go on dry, most of them have a circlip that's massaged into the ID of the boot between the piston and bore to secure it in place. I never tore apart a caliper with an integral parking brake - the hard part would be getting the piston back in and resetting the ratcheting mechanism that works parking brake. If anything, it would be like this guide: https://www.svocop.com/Articles/2/index.html
Very informative, thanks!
 
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