1987 4WD Pick-Up with NO BRAKES!!!!

The Fj40 King · 11-29-08, 04:46 PM

Hello

I'm hoping someone can help me out here.

Well, I'm a NEW proud owner of a 1987 4WD 4Cyl Toyota Pick-up.

When I got the truck it wasn't in the best shape.

So I decided to do some work on it.

I replaced the brakes and some rotten brake lines to the LSPV.

I also replaced the master brake cylinder.

I bled the cylinder and all 4 brakes.

After I finished bleeding the system I decided to test drive it

.

NO BRAKES!!!!!!

I stopped the truck with the clutch and parking brake.

I bled the system again.

No change.

I found out that the truck has a LSPV that also needed to be bled.

So I did and the truck only braked after the 3 rapid pumps of the pedal.

The 1st the truck doesn't stop.

The 2nd the truck has some resistance.

On the 3rd pump the brakes operate normally.

I have bled all the entire braking system multiple times with only a very slight difference each time.

What can I be missing?

I JUST BOUGHT A RUNNING '85 PTOYOTA PICK-UP FOR $150

raydouble · 11-29-08, 05:15 PM

What order are you bleeding the brakes in?

You have fluid at all 5 points I assume.

What does the pedal do?

The Fj40 King · 11-29-08, 05:33 PM

Hi

I bled the system in

Rear Driver
Rear Passenger
Front Passenger
Front Driver
LSPV

The brake pedal tightens as it should, but after 5 seconds or so the brake pedal is loose and goes all the way down.

If I pump it 3 times it tightens again, but after 5 seconds or so it loosen once again.

It is like it loses pressure.

I can't find any leaks, or see anywhere air can get into the system.

I have bled the system many times with little change.

I do get brake fluid when I bleed the system.

Thank you

inkpot · 11-29-08, 05:57 PM

Howdy! Did you Bench Bleed the new naster cylinder before mounting it in the truck? John

D'Animal · 11-29-08, 06:06 PM

Is the fluid level in the res dropping when you recheck?

The Fj40 King · 11-29-08, 06:11 PM

I did not bench bleed the master cylinder, but I have installed many cylinders before without bench bleeding them and they never give me any problems.

The fluid in the Res. does drop but only because it is lost when I bleed the brakes.

Other than that the fluid does not drop

GOT@TACO · 11-29-08, 06:33 PM

Quote:

Originally Posted by The Fj40 King

I did not bench bleed the master cylinder, but I have installed many cylinders before without bench bleeding them and they never give me any problems.

The fluid in the Res. does drop but only because it is lost when I bleed the brakes.

Other than that the fluid does not drop

How are you bleeding you brakes ? Are you bleeding with a jar and a 6``hose , put brake flued in jar open up and have somebody hit the brake p.... That will get all the are out . Good luck

ohrly? · 11-29-08, 07:00 PM

did you adjust the brakes?

The Fj40 King · 11-29-08, 07:04 PM

Hi

I have not tried the fluid in the jar trick, but I will.

The brakes are new, and I adjusted them as needed when I installed them.

Thanks for all the great support!!!!!!

GOT@TACO · 11-29-08, 08:15 PM

It works . I bleed my brake twice a year Just for fun .

Jukelemon · 11-29-08, 08:50 PM

Hi friend.

You really need to bleed with a jar OR a pressure bleeder. As well, when you use the jar, get a buddy to help you so that when the bubbles stop, your friend can leave the brake pressed-then you tighten the bleed screw.

raydouble · 11-29-08, 09:19 PM

Quote:

Originally Posted by The Fj40 King

Hi

I bled the system in

Rear Driver
Rear Passenger
Front Passenger
Front Driver
LSPV

You may need to bleed master before doing anything drastic.

Page 3
http://www.ncttora.com/fsm/1993/brak.../3checksan.pdf

inkpot · 11-29-08, 09:39 PM

Quote:

Originally Posted by The Fj40 King

I did not bench bleed the master cylinder, but I have installed many cylinders before without bench bleeding them and they never give me any problems.

The fluid in the Res. does drop but only because it is lost when I bleed the brakes.

Other than that the fluid does not drop

Howdy! I used to not do it myself, but I got into trouble with it once. So now I use the little nipples and bits they include in the box for that purpose. I used to just toss all that junk. I guess that's why they mention it in the instructions. I guess I was just lucky for over 40 years. You could even do it on the truck. Put a pile of rags under the MC, crack the fittings loose one at a time, and have someone pump the peddle for you, just like bleeding the wheel cylinders. HTH John

2ndGenToyotaFan · 11-30-08, 02:24 PM

Did you get a rebuilt master? Or a brand new one? Which brand? Bottom line is, if you aren't leaking fluid anywhere.... and after a few pumps you have pressure, but it drops off, the master is not holding the pressure... I got my money on the master.

KLF · 11-30-08, 02:29 PM

Does your e-brake work? Do you use it?

Setting the e-brake every time you park is what keeps the rear brakes properly adjusted. What I used to do back in the days when I had prehistoric drum brakes on my truck was get them close, then after getting everything put back together, get it the truck and yank on the e-brake handle about 15-20 times.

Pumping the brakes is usually an indication that there is something out of adjustment, usually the rear shoes.

But, another thing that can happen is if there is excessive runout on a front wheel bearing, this will cause the rotor to "wobble" as the wheel spins, which will open up the caliper. You then have to pump the brakes a couple of times to get them to clamp down. After you drive a few minutes, it opens back up again, so the process repeats.

The Fj40 King · 12-02-08, 06:24 PM

Hi again,

Well, I bled the brakes AGAIN, this time with the jar and brake fluid.

I did it in order and nothing.

Same results.

As for the master cylinder, I bought a rebuilt one.

I also suspected a bad cylinder, so I got an exchange on another rebuilt one.

SAME PROBLEM.

I doubt that both rebuilt master cylinder were bad.

I am guessing it will be the LSPV.

I will try getting one from the junkyard and post with the results.

Thanks for all the help!!!!!!!!

Jukelemon · 12-02-08, 07:27 PM

Are you doing it with a friend? You HAVE to use another person so that when the bubbles stop, the brake remains depressed.

Did you do this? It is not enough to just use the jar.

Hilux · 12-02-08, 07:48 PM

Ok, 1st off, I agree with inkpot in post #4.

2nd, I thought the two lines coming from the master were for the front and rear, separate not together.

If the LSPV is the little thing in the back, and you thought it was the problem. Wouldn't the brakes be fine on the front?

If so, I think you can rule it out now...

Did you bench bleed the 2nd master cyl?

Would a tear in the diaphragm have these results?

The Fj40 King · 12-20-08, 04:06 PM

Hi

Thanks for all the replies!!!

After some inspection, the problem was caused by one of the rear drum wheel cylinders.

One piston was getting jammed and wouldn't retract.

The cause was build of mold and rust.

I cleaned it, reinstalled it and bleed the brakes, and everything worked perfectly!!

Thanks again

Hiluxonian · 12-24-08, 11:28 AM

Quote:

Originally Posted by The Fj40 King

Hi

Thanks for all the replies!!!

After some inspection, the problem was caused by one of the rear drum wheel cylinders.

One piston was getting jammed and wouldn't retract.

The cause was build of mold and rust.

I cleaned it, reinstalled it and bleed the brakes, and everything worked perfectly!!

Thanks again

My truck does the same bled it several times changed components someone recently suggested adjusting/repairing the rear brakes glad it worked for you hopefully that is my problem too