1985 4 runner Brake bleeding/master cylinder

[dawg runner]

Hi,

Finally got around to finishing the brakes on the runner the other day.

First i went round and checked all fittings and nipples to ensure they were tight. We started the bleed process from furthest calliper away from master so passenger rear then driver rear and fluid was passing through fine.

Then moved to front passenger and as soon as we tried to bleed it seemed to lose all pressure on the pedal. I went round and double checked all fittings and nipples and checked resovior and appeared all fine. No leaks. Started again at the back passenger and was getting fluid then moved to front and lost all pressure again. I decided to persist as the back had taken some time to get fluid down the line but after about 15 - 20 attempts i had seen no fluid on front passenger side. Just to be sure moved to driver and tried about 15-20 times and no fluid. undid the fitting that provides fluid to the front callipers and it was absolutely bone dry.

Now my first thought is the master cylinder. It was working fine when it came off which was over a year ago but has been sitting under my bench in the shed for a while and could have pick any number of meterials that i have been hacking at on my bench. I am pretty sure it is the original unit as well.

As i said i pretty sure it is the master cylinder but just wanted to see if there was something i have overlooked.

Thanks in advance guys.

Dave

[RAY185]

Always pays to bleed the master cyl on the bench before fitting to vehicle. Pull it out and bleed it on the bench. If it fails to pump out the front port then rekit/replace it.

[dawg runner]

Thanks for the reply mate.

Where do i bleed the master cylinder from? Do i use the piston stopper bolt or what?

Thanks in advance.

Cheers

Dave

[RAY185]

Clamp the master cylinder in a vice. Put some sort of catch tray under the brake line ports to catch the expelled fluid. Block the 2 ports with your fingers and fill the resevoir with brake fluid. Using something long and blunt (eg,bit of rod/screwdriver handle, not your pecker) push the plunger in with your finger off the 1st port, put your finger back on and release the plunger. Repeat till the fluid comes out in a steady stream (no air). Then do the same for the second port keeping your finger solidly on the 1st one you just bled. If it all bleeds up well your master cylinder is fine.