metaron

Hi Guys,

The situation so far = I had caliper off the brake disc and my buddy pressed the brake pedal ALL(!) the way to the floor!!! I am 99.9% sure this has messed my Master Cylinder (MC) up. It is a RHD UK one too I might add.

I have tested the brake booster by pumping brake pedal till it goes hard then starting engine - the pedal then travels down as it should so I'm assuming the booster is good.

I have 2 options:

1) Disassemble Master Cylinder and repair the rubber boots/seals that have gone. (Has any one got lucky with this and been able to reuse the seals/boots before?)
2) Replace the Master Cylinder.


Regardless I know the Master Cylinder has to come off and then be bled when it's reinstalled but I have concerns about the ABS system and TRAC system - Do I just leave these alone? I was just going to clamp the hose from the brake reservoir going to the ABS unit before I emptied the reservoir as I did not want to mess with the ABS.

I have the 1999 service manual and on p438 it states

and soon below

Now I have the Haynes manual and the only thing it mentions in the Master Cylinder - removal and installation section is:

The Haynes manual doesn't mention the TRAC system at all regarding Master Cylinders.

Does anyone have the part numbers for a new Master Cylinder?

Any help from you fine gentlemen will be greatly appreciated.

metaron

Here is another shot from the side of the Master Cylinder in question, again if anyone has a Toyota part number that would be great.

salimshah

With the caliper off, the damage should be in slave pistons popping out and introduction of air. The pistons in the master travel longer than normal, which is not catastrophic. Exceptions are always there, but I would rebuild the slave and then bleed. I would then block the master and see if the pedal becomes stiff and only after this test, I would think about rebuilding the master or replacing the master.

The ABS will be a pain. The dealer has an electronic device that they use to bleed. The claim on the internet is that it not needed and you can still bleed the system. I have personally only bled the slave sides, so I cant verify the claims made on the net.

Salim

metaron

Cheers Salim

Well before I detach the Master Cylinder I'll have to empty the brake reservoir so I'm gonna clamp the hose to the ABS from the brake reservoir(see pic) as close to the reservoir as I can and keep it as high as possible too so HOPEFULLY the ABS wont be affected with any air.

I just need a tip on how best to bung/seal the 2 metal brake lines that go in the Master Cylinder now as I've never taken metal brake lines off before.

So my plan of action will be to:

1) Clamp hose from brake reservoir to abs unit.
2) Drain reservoir with syringe.
3) Remove and then block the 2 brake lines from Master Cylinder.
4) Remove Master Cylinder
5) Disassemble Master Cylinder and inspect damage(PICS TO FOLLOW)

Anyone else's input is always valued hopefully we can turn this thread into something RX owners can find useful.

metaron

On second thoughts Salimshah I have re-read your post and think your on the right track by leaving the Master Cylinder till last so I am first going to inspect the caliper then bleed it and see how it is.

carguy07

What makes you so sure that anything was damaged at all??

metaron

I think I've damaged something as the brake pedal now travels slowly all the way to the floor making me believe I've popped a seal/boot in the Master Cylinder(and hence now running on 1 of the 2 hydraulic systems) I'm just about to get that caliper off right now to have a look, gonna bleed it as well before I start messing with the Master Cylinder.

I've given the booster the operating test and the air-tightness test and all seems ok with it.

Anyway I'll know more in a little while.

metaron

I got some major delays to getting around to do these brakes anway never mind.

RE: brake bleeding - I notice that on left hand drive U.S cars the brake bleeding sequence is usually:

1) Right Rear
2) Left Rear
3) Right Front
4) Left Front

Now as this is a right hand drive U.K car with the master cylinder on the U.S-passenger-side is the bleeding sequence the same or would it now be:

1) Left Rear
2) Right Rear
3) Left Front
4) Right Front

As this would follow the logic of bleeding starting with the line furthest away from the master cylinder?

salimshah

[QUOTE=metaron;7440705

As this would follow the logic of bleeding starting with the line furthest away from the master cylinder?[/QUOTE]

You are correct .. understand the principle and then apply it accordingly.

Salim