Rear Brake Cylinder Replacement

[daveargie]

I have a TR4 with a serial number that starts CT 383 and need to replace my left rear brake cylinder which is leaking like crazy. I assume from what I've read that I have the .75" bore wheel cylinder rather than the later .70" bore but wanted to see if I'm missing anything. A couple of other questions....

-is there a wrong type of brake fuild, I'm a little confused from what I've read?

-is it possible to do this repair without need to bleed the entire line or can I put a stopper or something on the line I'm working on and limit the bleeding to just my left rear brake. I'm sure this sounds like a dumb question if you done this before but I haven't.

-anything else to keep in mind?

This brake fluid stuff sure is slippery.

Thanks

Dave

[Rhodri]

Dave, I have no idea what bore your cylinder would be, but you could measure it when you get it out. If one side has gone then the cylinder in the other side is on its way out. You could even change all the flexibles whilst you are at it, if they need doing.

 

Unless you have silicone fluid in the system use an up to date non-silicone type. Dot 4 is readily available here, but I believe there is a Dot5 that may suit- ask the seller. You say it is slippery, do you think you have silicone fluid in it?

 

You can clamp off the rubber flexible pipe on the axle with care so as not to damage it. If it is metal braided then I would not. A piece of a polythene bag put under the master cylinder lid will also help to prevent fluid loss. When the job is done you may then get away with just bleeding the rear brakes,or there again you may not.......!

[bob-menhennett]

Dave

 

If you don't already know/ have found out... tradtional brake fluid should be kept well away from paintwork because it acts as paint stripper.

Wear a face mask if you are going to blast the brake assembly with Brake cleaner ( just in case you have old asbestos brake dust in the rear drum).

Catch all the dirt/ fluid on old paper and put it into a sealed plastic bag a.s.a.p.

Once cleaned up put masking tape over the friction part of the brake shoes to keep them clean.When it is all back together again the final piece of work is to remove the masking tape.

If you don't have a proper brake shoe lever and are improvising with a set of mole grips, cover the springs with a strong cloth so that a tensioned spring doesn't make a break for freedom towards your eyes....nasty !!.Lever the end of the shoe opposite the adjuster to get it onto the refurbished cylinder.A diagram/ sketch of precisely where the springs, go before you dismantle is worth while.

Use coppaslip when re-assembling but never on the drum or friction part of the brake shoe itself.It's worth dismantling the adjuster whilst you are in there ,to make sure it all moves freely.Again brake cleaner or meths to clean up the parts.Wind it back in ,to make getting the brake drum back on easy, then adjust.

Cleanliness is everything especially with the cylinder itself.Soak the seals in a small jam jar ( an individual portion one ..like you get in a hotel are ideal ) full of clean brake fluid.

As Rhodi says if the three flexible rubber pipes look "past their sell by date" i.e you can see the rubber perishing if you bend it in a sharp bend, then replace

don't muck around with safety items your life depends it.

 

Which part of the country are you in Dave

[johnny250]

A couple of other questions....

-is there a wrong type of brake fuild, I'm a little confused from what I've read?

-This brake fluid stuff sure is slippery.

Thanks

Dave

 

The silicone fluid that I use is purple in colour, (I don't know if they all are) and must not be mixed with 'ordinairy' stuff that is usually clear/yellowish.

If yours is 'ordinairy fluid' it may be worth renewing the whole lot as it absorbs water from the atmosphere after a few years....but that does take a bit of time.

 

john