ORJ's Rear Brakes

[Matt Elan]

Right - I'll move this thread to where I should have put it!

I can see its going to be one of those jobs - just ordered up some more bits from Sue Millar - clevis pins, pad retaining pins and clips and the bolt to hold the pad spreading springs. Then ordered a couple of new solid brake lines and the flexible ones from SJSportscars as Sue didn't have any. On to Amazon for some rotary wire brushes silver smoothite and dremel wire brushes and polishing bits as all mine have disappeared - Garage fairies or have I used them - who knows?

Then spent the rest of the afternoon cleaning up the three lumps that make up the handbrake mechanism. All initially encrusted and now a bit cleaner - waiting on the dremmel bits to get them ready for paint:

Cleaner now:

More to follow; hopefully I'll get it all done before they lift the lockdown!

[Bigbaldybloke]

I went to Machine Mart and bought a small sand blasting cabinet as I already had a decent compressor, did a similar job in no time, well worth it for me as I've used it on numerous small bits now. Not sure if they are trading during this lockdown

[Matt Elan]

I do have a small blast cabinet but I've not got it set up at the moment! My plans for a new workshop on my drive have been rejected by the planners - Grrrr. So I've got to go to plan B to reclaim some space in my big shed in the back garden now, which means emptying all the junk out of it, running power down to it and using it as a workshop. Trouble is I can only get bits of car down to it!

[Bigbaldybloke]

Good luck with the planners, keep trying. I used to only have a bench grinder with a wire wheel on it, and it did a good job eventually. Things progressed much quicker once I got the sand blaster installed and working.
My garage was a real mess, all sorts of junk, bikes, bits of bench and random shelves. The Lotus had been sat amongst this lot for some years unloved. In the end I emptied the garage completely, painted the walls white, the floors grey and rewired it with plenty of sockets. Then it was new lighting, bench and set up the compressor, lathe, milling machine, blast cabinet, pillar drill, bench grinder and shelves and racking. Lot of work but really worth it, everything to hand now and room to work, although a couple of bikes have sneaked back in.
That was a couple of years ago and of all goes to plan the car should be back on the road later this year. Current job is bleeding brakes and clutch, have to admit to cheating and getting exchange refurbished rear calipers in the end, mine were just too worn for me to refurbish to a standard I wanted.

[Matt Elan]

Dremmel bits arrived so it was out with the mini wire brush to get the last bits of rust and dirt off:

Then hang 'em high - and hope the dog gets out of the way before I spray....

and a few squirts of Silver Smoothite later:

and its like watching paint dry. Luckily the dog is still liver and white...

[Matt Elan]

So with the handbrake mechanism painted I turned my attention to the caliper. As you can see it is pretty grubby. Even after a quick going with the dremmel nylon brushes to get the worst of the muck off it wasn't that good!

So I couldn't get the pistons to move either and when I peeled back the rubber bellows I found this:

Yep - that a piston siezed in place; I thought the rear disk looked a bit rusty when I took the cliper off - should have looked more closely. So new pistons and seals on order - just got to persuade the old pistons out now.

[Matt Elan]

Pistons came out of the caliper with a little persuation from an air line:

I think I'm justified in ordering a new set! In fact I'm surprised they were not leaking....

The first piston popped out happily with the air pressure and the second one moved a significant amount. And while fruitlessly searching for one of my several pipe wrenches to twist the second piston out I found a couple of rotary wire brushes - I knew they were there somewhere. Mind you I didn't find the pipe wrenches so I carefully levered the second piston out with a pair of screwdrivers....

[Bigbaldybloke]

Are you going to order stainless or standard chrome plated ones?

[Matt Elan]

Hi bbb I’ve ordered standard onesm SJSportscars. Used them in my other Plus 2’s brakes and they fitted and seemed decent quality. And SJSportscars had them in stock and I’ll hopefully get them next week. I probably should have gone for stainless but they are on order now. Should get a good 15 years out of them hopefully and by then the seals will need doing anyway.
I will be appealing the planners decision to turn down my garage. Process seems straightforward so nothing to loose

[Bigbaldybloke]

Good luck on the planning, most appeals seem to go through with a few minor tweaks.
The pistons seem to sweat and rust inside the rubber boot seal, copious quantities of grease in them should help.

[alan.barker]

I fitted Stainless Pistons in my Sprint rear Calipers.
The cheapest i found were from "Farrel" in USA, cheaper than from UK including postage.
Alan

[Matt Elan]

And with the prospect of rain later today and tomorrow, and finding some old masking tape it was time to give the wire brushed caliper a quick spruce up with some more silver smoothite:

Next job - reassemble when the new seals and pistons (and the rain) arrive!

And I've got new bleed nipples on the way as well so don't worry about the painted one!

[alan.barker]

Hi Matt,
looks very good.
Alan

[Matt Elan]

Thanks Alan - anythings better than they were!

[JJ66]

Condensation can develop inside the rubber dust cover, that's true, but the biggest issue for caliper pistons is water in the brake fluid. Its easy to forget with our cars as they are often not used as much as a regular driver, but brake fluid should be changed every 18 months (2 years at the outside) because it is hygroscopic which means it absorbs water from the atmosphere. This reduces the boiling point significantly over time which leads to cavitation and 'lost' brakes when driven hard, but from a maintenance point of view it also promotes rust on pistons (inside the caliper) and in brake lines, and also does bad things to the servo's that are fitted to our cars. Its really important to bleed thoroughly and purge old fluid out of every nook and cranny that you can! One of the replies was to grease the piston under the boot, this is OK to do but be sure to use vegetable based grease (the crimson coloured stuff) and not mineral grease, that will cause the boots and seals to swell (this includes copper grease, keep it away from the boots). Happy Braking! Jonathan