calipers

[furore]

hello all,

I had the front brake calipers of my '2 at the weekend for refurb and discovered that slider boots had split on one of them and let the weather in. The slider is pitted, and the inside of the caliper is rusted. Given the grooving on the inside of the caliper, I don't really see how i'm going to get it back to good condition so i'm probably going to buy a remanufactored caliper. My question is, should i replace both the front calipers? The other one seemed to be in reasonable condition, but i know you would do everything else on brakes in pairs.

-Matt

[Jim-SR]

calipers arent really wear items, they are just lumps of cast iron with a steel piston inside. so long as the pistons are the same size and there are no faults in the operation of either caliper, it makes no difference if one is brand new and the other is ancient and refurbed. so long as everything slides without resistance it wont make a difference

id just get one reman. caliper and refurb the good existing one. its not like pads and discs where replacing one side can lead to the brakes pulling around, etc

[System-G]

When you say the Slide - do you mean the actual slides that allow the calliper to move in the carrier or are you refering to the piston.

If I am thinking right, I think you are talking about the slides that allow the calliper to move in the carrier. If thats the case, then as Jim said the calliper itself is cast - the rust on the outer surfaces does little to hinder actual performance.
The slide itself "floats" in a durable plastic (or in some cases a metal) race. These are replacable if you get the full refurb kits from Brakes International or Camskill.

If it's the main piston and cylinder that is showing scoring, you may need to get a replacement piston. The cylinder can be rubbed down to be clean and rust free, but as this does not actually dtouch the piston, you should be OK. The piston is held and sealed in place by an O-Ring. Replacement pistons are also available from the two places above and are not part of the refurb kits.

[furore]

I don't mean the piston, that's fine. I've graffitied a bgb image:




The slider busing (A) is pitted. There is quite a lot of rust inside the bit of the caliper this sits in (marked as B). I can't see how i'll get that rust out without just attacking it with a round file, and that still won't move the rust out of the groove thats machined into the caliper in there.

Thanks for the help, by the way.

[System-G]

Yup Slide "A" actually sits (or floats in grease) inside a collar/ferule/race which is situated inside "B". These could be made of grooved plastic/teflon or steel. A good cleanout of "B" should clearly reveal all.

If you get the full-on refurb kits from brakes international, they contain the replacement slides and races. But it's a real PITA to replace the races - you may need a fair amount of heat and a press.

The other alternative is to buy an already refurbished calliper off Brakes International and send your old one back for refund of the surcharge

[DNOS808]

I gave Big Red caliper refurbishers in Worcester a box full of Mk1 calipers to save them from scrapping. They will probably have them waiting for an order for a refurbished caliper. They are good value for money.

[furore]

Thanks for the advice guys . I cleaned out the caliper as well as I could, put it back on and sent it for MOT. It's passed ok , although i've not seen the sheet yet so I don't know if there is a warning or not. I'm not sure how much longer I can keep the car going now (rust situation is getting beyond what I can fix ), so will probably hold of on the replacement all the while i'm sure its still safe.