Toyota break bleeding problem?

Question

I have just got a 1993 hilux 4x4 pickup, I have put new callipers on the front because the old set where seized except two of the pistons! But my problem now is I cant get tht system to bleed. When i open the bleed valves i get fluid but i can just pump & pump the pedal (got no pedal is the term used) So is it the master cylinder! how can i be sure be four i spend £130+ on a new one

Answer 1

have a look at the master cylinder and see if there is a hexagon nut (about 10mm)attached to it .this is a bleed s***w for the master cylinder .it could be air trapped in the cylinder .if there isnt a s***w try undoing the brake pipe at the master cylinder and bleeding the system.if the brakes where ok before it could be the rubbers in the master cylinder have got dry because of fluid shortage .

you could try clamping the brake hoses and if the brake pedal goes hard when the pipes are clamped  the problem in the side thats clamped.....

Answer 2

As above, best to get yourself one of the pressurised one man bleeding kits for quick results;

http://www.halfords.com/webapp/wcs/store...

Answer 3

I would try to strip it first and clean it  and check seals

You may get them from a specialist o ring  / bearing supplies

Or get the unit overhauled by a recon company ?  with a stainless sleeve fitted inside ?

Maybe you need to remove calipers and twist them upside down incase of an air lock ?

Or try and reverse bleed with an oil can ?

Good luck  

Answer 4

Are there 2 people doing the job? It sounds from your question that your going to the caliper, opening the bleed valve, running back to the drive seat and then pumping the pedal. Of course you would lose pedal pressure if you're doing it this way!

The proper way is with 2 people. After filling the reservoir, you pump the pedal until its well firm. Then you keep holding it down. At that time you have an assistant open the bleed valve. The pedal should fall to the floor and as it reaches the bottom shout to your friend and have him tighten the valve. Then you repeat until air bubbles are gone. Then you check the reservoir and add fluid because you need to replace what you pump out.

If I read it wrong and you were doing the procedure correctly then check the lines and calipers for any leaks. If you don't find any then it is the master cylinder. Pistons binding will not cause a low pedal problem.

Answer 5

I have the same truck [91 model] and had the same probs as you! However I am not a mechanic and had it AA'd to my local 4x4 garage, they checked it out and found it to be the master cylinder! This answer does not inform you how to be sure, but anyway I wish you good luck! ....... Brilliant Truck when sorted out!

Answer 6

HI

First off You do know how to bleed the brakes right??

You can't do it by your self unless you have a one man bleeding tool. or it take two (2) people.. one to pump up and hold the brake pedal while the other opens the bleeder and CLOSES the bleeder before he takes his foot off the pedal after it reaches the floor board. If you take your foot off the brake pedal while the bleeder is open you just suck air right back into the line.

good luck

Tim