Rear brake cylinder piston lubrication

Post by **pmdavies** » Mon Aug 06, 2007 7:06 pm

Hi guys (and girls!)

I’m overhauling the braking system on a ‘67 Minor. Got the rear cylinder apart and cleaned everything up. All looks ok so am going to go with it. Can’t find anything in the manual about lubricating the pistons in the bores. Obviously the main hydraulic piston is lubricated with brake fluid but what about the secondary piston that the hand brake lever operates? I’m tempted to use grease for this one as brake fluid would tend to drip out of the ‘port’ where the hand brake lever enters the cylinder bore.

Anyone know the correct method? If the answer’s grease, any particular type? Views appreciated, hoping to finish it tomorrow!

Many thanks, Pete

Post by **bmcecosse** » Mon Aug 06, 2007 8:34 pm

There is special red 'rubber' grease for this job - but I have used silicone grease here without problems. DO NOT use ordinary grease!!

Post by **rayofleamington** » Mon Aug 06, 2007 11:58 pm

any grease will melt if it gets hot, so it could drip into your brake drum

However I've tended to ignore that and use grease anyway (on the lower piston and handbrake lever and on the backplate to help them slide) when rebuilding old cylinders - they need all the help they can get. The grease won't drip upwards onto the hydraulic piston (but yes - it's not ideal to have any type of grease anywhere near your brakes! If you use some. make sure you use only a smear as that's less likely to go anywhere it shouldn't)