'66 Cj5 Tux Resto-mod

Well I got one run of wires done. Kinda hard working 9-5 it really cuts down on my garage time!


Got some High temp loom coming this weekend to wrap it all up. Onto the RH front tomorrow.

 

@timsresort you run a Summit Mojave heater right? Where did you install the quarter turn valve that came with it in the lines?

 

Also wanted to ask @Fireball - on my to do list is to tighten down the U-joints on my driveshafts. Does it look like I have them phased correctly? There were several sets of pin marks on them that were impossible to match back up, I should have ground them out and made my own but I forgot.

 

Yes, they look correct. The yokes on both ends of the shaft need to be aligned with each other for proper phasing.

 

Thank you!

 

Don't want to nitpick, but I always put the slip yoke up. Kind of keeps it out of the mud a little more, and the spline can drain also that way.

 

I didn't use it, I didn't see the point.

 

Maybe you guys can help me. Just had a super frustrating evening in the garage. I had two buddies come over and help me try to bleed the brakes, and I cannot get any fluid to come through the front.

The last time I did this with the old calipers, there was no problem, but now it seems like the proportioning valve is somehow stuck and will not let any fluid go through to the front regardless of where the dial on top is positioned.

I tried it with the knob all the way up counterclockwise, all the way down clockwise, and everything in between with both front bleeders open while someone was pumping. No fluid.

I also tried taking the banjo bolts off and looking to see if fluid is coming through the hoses and it was not. Tried new washers and two brands of bolts.

The pedal is super stiff and no fluid is going down out of the front tank. Does anyone know how to troubleshoot this proportioning valve, or what could have happened between replacing the front calipers and now that would affect how it works?

heres a pic:

 

Those proportioning valves do nothing to the front circuit. It just passes through. They reduce the pressure to the rear circuit only.

My guess is that the master cylinder needs to be re-bled for the front circuit? A pressure bleeder or a Mity-Vac would probably help pull fluid through whatever air bubble you are dealing with.

Although a "super stiff" pedal doesn't really jive with that. If you crack the front line at the master cylinder are you getting fluid coming out when you push on the pedal?

 

I was looking at phasing only and didn't even think about orientation. I've always seen them with the slip joint up but hadn't thought much about the reasons. I like your line of thinking.

 

Maybe since the rears are solid, it's making the pedal stiff, and won't travel enough to bleed the front. I kind of doubt the prop valve matters. I don't know if you saw the gravity setup I did, and that was the only way I could get the air out of the front calipers. So when you disconnected the front line, there was nothing? Not a burp or drop? I picture the rear full and solid, the front full of air, and the pedal not moving enough to push fluid to the front. Also, in my recent experience, if there is one bubble in the master cylinder, it won't push fluid, you may have to bench bleed it again.

 

That is exactly what we saw. So - how do I fix it? To bench bleed the MC does it have to come out? I don’t even know that I could get it out right now.

 

You don't have to take it out. Disconnect the front line, connect a bench bleed tube (just make a 3/16 line flared on 1 end) to the port that loops up and into the open front reservoir. Press the pedal, you will get air to burp into the reservoir, then suck fluid in on the upstroke.

 

You could try un-adjusting the rear brakes in as far as you can to get more pedal travel.

MityVacs https://www.amazon.com/MV8000-Automotive-Tune-up-Brake-Bleeding/dp/B00265M9SS can be helpful in these situation because it can pull a vacuum on the bleeder and pull the fluid through without the limitations of pedal stroke.

You can also try to do a redneck speed bleeder. Loosen the bleed screw a little bit, put you finger over the end of it with very light pressure and have someone rapidly pump the pedal. Your finger works as a one-way valve to prevent air from getting sucked back in, but unlike opening/closing it with a wrench, you can pump the pedal rapidly.

 

Thanks you guys. The wife slow cooked a lamb leg to feed my friends who came over and helped me and they just left, so I now had the chance to read through your suggestions and try to understand what’s going on.

I will crack the front lines and verify fluid coming out, and then blench bleed the MC the next time I get a chance and start over.

I really want to learn about what is going on- hopefully you can help me get there - Sorry if this is a dumb question.

I understand that when my LF caliper burst, all the fluid got pushed out of it, and the line to it likely got full of air. But - How did air get all the way back into the MC, when the level of fluid in the MC never got down below the drain holes? And if there’s air in the lines, how come the pedal being pushed down didn’t just push the air bubble out the front lines with fluid from the full reservoirs pushing it out?

We had both front bleeders open, and the pedal was really stiff with no fluid or air coming out at all when depressed. Just pumping over and over with no change in fluid level and no fluid traveling out the bleeders….until we gave up.

Could my mechanism of clear hose over the bleeder into a plastic bottle have been part of the problem?

 

It seem like one of two possibilities:

1. The leak siphoned everything out of the master cylinder it needs to be re-bled. If the master cylinder wasn't completely empty, this probably is not the case.
   
2. The leak caused a big air bubble in the high spot where the pipe goes over the frame. With the rear brakes adjusted and bled, you don't have enough pedal travel to work that bubble through the system. When you did it the first time around, the rear brakes weren't limiting your pedal travel as much and you didn't hit this issue. Since some of the brake lines are higher than the master cylinder, you can't gravity bleed it. The is one of those cases where a pressure or vacuum bleeder can be helpful as they aren't limited by pedal travel.

 

That makes a lot of sense, thanks. I ordered a pressure bleeder kit and will give that a try this weekend.

This video also seems to explain the symptoms I was experiencing:

 

The more I think about this I’m inclined to think the piston in the proportioning valve went all the way to the front when I had the front hoses off to change the calipers. This is what it’s designed to do right, in the event of a hose blow out ?

That would explain why the hoses drained for a few seconds but then stopped and didn’t drain the MC. This makes more sense to me than an air bubble. I can probably check for continuity across the switch to confirm.



So the question then is - how do I move it back to center to reset the valve? This guy suggests opening all four wheel bleeders and smashing the pedal down to send it backwards….or blowing compressed air in the fronts. Any other ideas? Will pulling vacuum with the bleeder pump I ordered be sufficient?

I feel like @Focker would know what to do.

 

That procedure is for distribution blocks with brake warning light switches. If the pressure goes out in one circuit, the pressure imbalance between the circuits pushes a piston to actuate a switch and turn on a warning light on the dash. It's suppose to let the driver know a circuit has failed. (From past experience, you really don't need a light to figure this it. It's a LOT harder to stop.) To reset these you typically open a bleeder on the circuit that didn't fail and push the pedal firmly until the light goes out, but not so firmly you force the piston the other direction and turn the light back on. This system is very common in OEM distribution blocks.

All that said, I don't think that's your problem. All the instructions I can find for similar looking aftermarket distribution blocks/proportioning valves say it's simply a pressure activated brake light switch. If that's the case, there would no sliding piston:

• https://www.jegs.com/InstallationInstructions/800/884/884-A0730PL.pdf
• https://www.classicperform.com/Instructions/PDF/APV-DB.pdf

It's easy enough to see if the front circuit is blocked at the distribution valve. Remove the line from the master cylinder to the distribution block, also remove one of the front brake lines form the distribution block, and genlty blow through it with an air nozzle. My guess is it's just a hallow pass though and it's not blocked.

 

Ok gotcha. Well then let the troubleshooting begin. Fireball what would you try first, then next to fix this? Want to make a game plan for the weekend.

1) Use the pressure bleeder to suck fluid through the RF bleeder, then the LF bleeder, while keeping fluid level up in MC?
2) Attempt to bench bleed the MC?