60 brake proportioning valve

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snowboardonsnow

snowboardonsnow

10 Year 15 Year
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Jun 22, 2009
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Tacoma, Washington
Here is the down low, its been like this since I have had the rig but I can not bleed my rear brakes. On several occasions I have tried (forgetting it doesn't work).

What gives? is in the proportioning valve? there is Nothing coming out of the rear.
the fronts work great btw.
 
Try cracking a line loose on the back of one of the rear brake flange plates. If you get any seepage there when pumping the pedal, then the problem is inside the wheel, like a blocked up wheel cylinder. You could also pull out the bleeder valves and see if they are blocked also. John
 
inkpot said:
Try cracking a line loose on the back of one of the rear brake flange plates.
Click to expand...

Thanks John, I tried that.

Any other things? I guess I will try cracking right off of the MC and see if that does anything.
 
In some cases the p-valve is part of a larger assembly referred to as a "combo valve." One of, ot he only other component depending, is a shuttle pin designed to close off which ever system has failed. One end of it sees front brake pressure (pre- pre-valve) and the other end see rear brake pressure. When either is too low relative to the other the pin moves a short distance inside and shuts the exit port on the low side.

If this pin is present and moved in the bleeding process it could explain the symptoms. Most have a reset method listed in the FSM.
 
Thought I'd bump this thread for advice for a similar problem I'm having.

I just rebuilt my front calipers, new rotors, and pads in the front- 87 FJ60. Bled the front and decided to try and bleed the backs as well. I'm using a vacuum pump to do it solo.

I couldn't get any fluid- not even a drop- out of either rear brake cylinders. As far as I know, they haven't been touched in a long time- maybe ever.

I'm not too worried about it, as my next project was going to be a complete rear axle rebuild, new cylinders, seals, etc.

I didn't see a LPSV anywhere. Any thoughts?
 
For a 60 there is no LSPV, only on the 62s (at least that is what I remember). It may be time for new wheel cylinders for you guys. I actually just did this on Friday with new shoes and took me about 5hrs total. I still got some other things to do but seems to be working great after the new M/C and now the new wheel cylinders. If you pull the hard line from the cylinders are you getting any seepage or anything?

If you are truly not getting anything out of the bleeder valve it is time to crack open the rear wheels and see if it is seeping inside. For piece of mind you may just want to replace the cylinders.
 
Nothing even if I crack the rear hard lines. I am just going to (yah havnt done anything yet!) Get a new master as the problem must be in there somewhere. It's really bad when you are doing a hill climb and your not in 4x4 if you don't make it it can be a scary back down as yourjust slide like you pulled the ebreak, gotta shift it in reverse super fast and use the clutch as a brake.
 
snowboardonsnow said:
Nothing even if I crack the rear hard lines. I am just going to (yah havnt done anything yet!) Get a new master as the problem must be in there somewhere. It's really bad when you are doing a hill climb and your not in 4x4 if you don't make it it can be a scary back down as yourjust slide like you pulled the ebreak, gotta shift it in reverse super fast and use the clutch as a brake.
Click to expand...
IF the problem is in the master, then you MAY not need to do anything to the wheel cylinders. You could try cracking the hard line on the side of the master to see if you have pressure/fluid up there. John
 
I don't know that a USA model FJ60 has an LSPV....

Seems like a new master cylinder is in order?
 
I would check the brake line from front to back as well... it might have a pinch some where..... P valves suck...... I pulled mine out as well as the abs from my 80's frame swap.....
 
Actually LSPV's are a great idea. Add more rear braking ability as the load increases. Perfect scenario. The problem is that all of the typical mods (larger tires, lift, etc.) take the whole system out of the range where the LSPV can function as intended.

Note my post earlier in this thread. If there is pressure at the m/c then work your way down the rear brake plumbing and check for pressure at every tube nut. The problem will be between the tube nut that does have pressure and the next one which doesn't. Would not surprise me if those were the in and the out of the combo valve.
 
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Oh and most brake lines are 10mmx1.0thread by 3/16 OD import standard flare (not bubble). I was able to pick up lines at Oreilly but they have them under 4.7mm for some reason, same with Autozone.
 
Mine (LSPV) leaks, anyone know what I can replace with? T-100?, Runner? Tacoma? Bypass and get rid it?
 
nmcquillan said:
Mine (LSPV) leaks, anyone know what I can replace with? T-100?, Runner? Tacoma? Bypass and get rid it?
Click to expand...

You can bypass it, but your rear tires will block easily, even if you don't brake that hard. It's quite annoying if people constantly look at you like you're an idiot who drives like a not too intelligent schoolboy who likes to impress the girls, every time you brake. :meh:
Don't ask me how I know...
 
Noted...thanks for that ...how about any suggestions on where to find the parts? Ive been all over With no luck. Does the part convert to a differant model?
 
BigBlue84 said:
I have the same issue. Was there a solution?
Click to expand...

If there's nothing coming out of your rear bleeders, they're absolutely clogged. Probably gonna have to replace them and if your drums haven't been given any love in a while, might as well do that while you're in there. It's all pretty simple and inexpensive. Advics brand is OEM Aisin. There are cheaper options, too.
 
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