# Rebuilding calipers. Must do seals?



## cmendes0101 (Sep 12, 2008)

I finally got around to taking out the pistons on a set of Boxster calipers so I can eventually sandblast and powedercoat. 
I was looking up pricing for the dust boot and seals and it gets very pricey.
Dust boot: 
20 4872 44 - 36mm - $8 x 4 = $32
20 4872 46 - 40mm - $8 x 4 = $32
Pressure Seals:
36mm seal - $16 x 4 = $64
40mm seal - $15 x 4 = $60
So around $180 and those were hard to locate for some reason but thats the best price I've been finding.
The calipers were very good condition inside, no gunk build up, all fluid was about clean brake fluid and the cylinder walls have no scratches or nicks. The brakes are were from a scraped '04 boxster and did not have that much road time.
If I were to pop the dust boot out and the pressure seal out for powder coating is it rule of thumb to *always* replace those or is it only if needed?


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## DaveB1970 (May 6, 2009)

Long Time lurker - dont post much...here goes..
I overhaul and refurb probably 8 sets of porsche calipers a month.
If you plan to powder coat the caliper then the fluid seals do need to be removed. You need to use compresed air to remover the pistons and dust caps and then verrrrrrry carefully remove the fluid seals using a dental pick or something very similar. Immediately get these seals in to a zip top bag and ensur they are immersed in CLEAN brake fluid. These can be resused - if they have had an opportunity to get dry then throw them away.
If you speak to your VW parts guy - on every front brake page for every model is a tube of lithium based grease i think its G 000 525A from memory this stuff is the same stuff as porsche use to rebuild their calipers made by the same people.
Those prices are insane for seals and dustcaps, the Porsche dealer can sell the dust caps for 986 boxtser and 996's so just give him the caliper part number 986.351.421 & 422 and he'll find the dust cap set. Its two per pack so you only need 4 packs to do your calipers.
What might also be an idea is to speak to Brembo distributor in the UK
http://www.racepads.co.uk/
Here you can get seals for all sizes that will work in the porsche caliper dont know about shipping to the USA though.
Alternatively you could purchase "Gasket Sets" from the 993 Carrera 2 these kits contain a dust cap, fluid seal and a piston they are exactly the same as in the 36 and 40mm Boxster front, I rebuild 996 Front calipers with these kits all the time
The Gasket sets:Fluid/Dust/Piston 3 items are....
36mm - 951 351 919 10
40mm - 951 351 919 11
The packets of 2 Dust Caps are as follows:
36mm 951 351 917 00
40mm 951 351 917 01
Your pistons should be reuseable if there is no corrosion on then.
I have had some "Lids" machined by a local machine shop to cover the pistons when they are being powder coated, they are basically discs as wide as the dust shield with a rebate machined into the back side so they "sit" in the channel where the dust shield goes - I put one over each piston and put a threaded bar between the two to seal the piston - works a treat. Nothing better than seeing a fully sandblasted caliper with the annodised bores looking black and healthy.
Hope the Porsche part numbers work ok for you


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## cmendes0101 (Sep 12, 2008)

*Re: (DaveB1970)*

Thanks, All that info helped alot. Just took out all the seals and boots to get ready for sandblasting. What type of blasting media is best for this? I just have alot of silica sand since I bought a bag to try out the gun when I first got it.


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## akjell (Aug 7, 2010)

*Interesting Issue with Brembo 40mm - 951-351-919-11*

I have a set of Porsche Boxster Calipers I am rebuilding and one of the pistons was in bad shape, so I ordered kit number 951-351-919-11 (40mm) from Paragon Products. While the dust seal and bore seal worked fine, the piston is actually 3mm longer than the stock brembo piston that comes in the Boxster caliper -- stock piston measures out to 40x30mm and the one in the parts kit measured out to 40x33mm. 

Is this normal or do you think I got a bad kit?


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