I had the front (disc) brakes on my Beetle sieze on while on the way to Strouds anniversary trial last year. At the time I changed the calipers and finally got round to looking at the old ones last week.
The problem ones weren't that old, around 4 years. When I took them apart I saw that the cylinders were corroded outboard of the sealing ring. The bores inboard of the seal (where the brake fluid sits) and the pistons were fine.
The protection seal was fine, no holes and seated properly. I believe that water got in when using a pressure washer to clean down. I am a bit religious with this and jack the car up and take the wheels off to clean underneath. No more pressure washing for me!
Michael
I have had similar problems with the P16 calipers on my Troll and I do not use a pressure washer. I use a low pressure hosepipe and a brush because I am sure pressure washers cause lots of problems to certain mechanical bits. I have also had a similar problem with the cylinder I use for the hydraulic handbrake. I think that the problem may not be pressure washer but due more to condensation which forms on the pistonin the area between the hydraulic seal and the protective cover. However I do know that a pressure washer will force water and grunge into my front wheel bearings that are Spitfire hubs etc. and have one of those old fashioned seals that are made from felt which you soak in oil. However my pressure washer does a wonderfull job on the wire wheels with no bad side effects. Stuart Harrold
ReplyDeleteI've also found the quickest way to knacker the front wheel bearingts on my Imp is to pressure wash around the suspension side of the front hubs and then leave the car to stand for a few weeks. I still use the pressure washer but I keep well away from the hubs and dig the mud of the suspension arms by hand (sometimes....)
ReplyDeleteStuart Cairney
Grease Is The Word Please continue to pressure wash you cars everybody, it is not only polite to scrutineers to present you car in a clean condition but a legal requirement. Just remember that a postscript to post event washing should be a session of preventative maintenance with the oil can and grease pot. Brake bits, bearings, CV joints, ball joints are all suceptible but easy to protect with copious amounts of grease. Michael - Next time you have the disc pads off, ensure there is a good quantity of grease on the back face of the pad, and around the pistons. This will help the pads from siezing to the caliper, and keep 98% of the water off the pistons.
ReplyDeleteSimon, Any advise on the grease to use around the brakes? I used to use copper slip. Just got some ATE stuff from Murray thatb he says I can use under the seal of the piston. Michael
ReplyDelete