Axle and brake help

[70STOVEBOLT]

I have no experience with them, but I have seen a lot of bad reviews on the brass PV2 valves. I would rebuild yours if you can. The are not complicated.

[Kalums]

Originally Posted by 70STOVEBOLT

I have no experience with them, but I have seen a lot of bad reviews on the brass PV2 valves. I would rebuild yours if you can. The are not complicated.

I will try and get a picture in N a minute but... That thing looks like someone dumped a swamp in the the insides and I can't get the "valve" to move even after disassembling what I can. If anyone has a rebuild guide... That would be greatly appreciated too. What about the M/C? I (re) bled it after taking the proportioning valve off and the reservoir for the rears doesn't really build pressure... I can put my thumb over the bleed hose and fluid just squurts/sprays out of the reservoir (reverse flow).

[70STOVEBOLT]

The master cylinder has to be bench bled. You are not trying to bleed it on the truck are you?

[Kalums]

Originally Posted by 70STOVEBOLT

The master cylinder has to be bench bled. You are not trying to need it on the truck are you?

I thought you meant was I trying to find a reason to buy a new one... I've always bleed them on any truck I've owned.. Honestly not sure what difference is, in or out of the truck makes if reservoir(s) are level and you can easily pump the cylinder till the bubbles stop. Educate me...

Less worried about that and more interested in why the fluid is shooting out of the orifice where it normally pulls fluid in AND why it doesn't pressurise enough to push my thumb off the bleed hose.

[dmjlambert]

Regarding the combination valve, I sent mine to White Post Restorations and had them rebuild it. I preferred that compared to going through hit or miss on chinese all-brass valves that are common. I re-read the thread and I don't see mention of your rubber brake hoses, how old are those?

[Kalums]

Originally Posted by dmjlambert

Regarding the combination valve, I sent mine to White Post Restorations and had them rebuild it. I preferred that compared to going through hit or miss on chinese all-brass valves that are common. I re-read the thread and I don't see mention of your rubber brake hoses, how old are those?

About a week old... I just swapped all three when I did the rear drums, mainly because I was already there and they are cheap and easy. I wasn't sure how old they were and they were caked in dirt and grease kinda figured they probably already collapsed.

Regarding everything else.... I've decided to just send the whole kit in to White Restorations. Final straw was when I cracked loose one of the nuts for the M/C on the booster and got sprayed in the face with brake fluid under pressure. About a cup of fluid leaked out over the next few minutes... So yeah whole new setup for me. Anyone know the part number I'm looking for, for that 1 ton vacuum booster? Possibly a source or part number for the M/C depending on what White Resto tells me on Monday? I've already got a quote on the cast iron proportioning valve, forgot to ask about the M/C and didn't know about the booster at that time. Thanks again everyone.

[70STOVEBOLT]

Every master cylinder I have ever replaced, the instructions said to bench bleed the m/c. I never tried to bleed it on the truck.

[Kalums]

Originally Posted by 70STOVEBOLT

Every master cylinder I have ever replaced, the instructions said to bench bleed the m/c. I never tried to bleed it on the truck.

At this point it is negligible either way (not trying to be rude I promise) I cracked loose the bolts holding the M/C to the booster and got pressurized brake fluid to the face(good thing I wear glasses)... Found out where all the pressure was going *facepalm* and didn't even realize that it was leaking into the booster, so I will be sending off the proportioning valve to White Restorations and hunting for a new booster and M/C. From what I can find the master cylinder that I currently have is NOT the original as it is stamped "made in China" and it looks to be the "Moraine style"? There was a different kind(style) M/C in the floorboard when I got the truck that has an AcDelco P/N. I've found both of those at Napa near me... I'm not exactly sure how to make sure they are what I'm supposed to have but I'm going to give them a shot, fittings seem to be correct but bore size on Moraine style is 1-1/4 and this one is 1.125 (1 1/8?). I can't find anything on stroke length for either of them.

NAPA P/Ns: Brake booster - NBB 5471007
Master Cylinder - NMC M36246

[70STOVEBOLT]

No offense taken, I’m glad you found the issue. If you use the search function you will find many threads on this subject.

[Kalums]

Originally Posted by 70STOVEBOLT

No offense taken, I’m glad you found the issue. If you use the search function you will find many threads on this subject.

I have, but there are a few threads saying different ppl have used either, the booster is correct. I'm not sure exactly which Master Cylinder to use yet I've got it down to 2 different ones.

P/Ns : M2085 (Moraine style) it was on the truck
Or : M36246 this is the one that was in the floor board.

Now remember this truck has a 1 ton Dana 70 dually rear axle with 13" drum brakes.

Any help or advice would be greatly appreciated.

[70STOVEBOLT]

Either style booster should work as long as the correct master cylinder is used in combination. Having said that, I can’t say which master, as I have no experience with 3/4 ton trucks. I’m sure someone will chime in with the answer.

[Kalums]

Originally Posted by 70STOVEBOLT

Either style booster should work as long as the correct master cylinder is used in combination. Having said that, I can’t say which master, as I have no experience with 3/4 ton trucks. I’m sure someone will chime in with the answer.

Hope fully *crosses fingers*

[Steeveedee]

A thing to watch for when you buy the new master and booster is the depth of the hole in the master cylinder piston. Don't remember which gets deep, or which get the shallow hole, but if you have it in your hand, it'll be an easy check, and an obvious difference. Should be OK because you aren't changing out the bell crank behind the booster, are you?

[Kalums]

Originally Posted by Steeveedee

A thing to watch for when you buy the new master and booster is the depth of the hole in the master cylinder piston. Don't remember which gets deep, or which get the shallow hole, but if you have it in your hand, it'll be an easy check, and an obvious difference. Should be OK because you aren't changing out the bell crank behind the booster, are you?

I was not planning on changing that or messing with it at all to be honest. Thank you for the heads up on the depth.

[Kalums]

So Update...got all the old parts off, the booster was almost full of brake fluid �� I got a new brake booster and "Moraine style" master cylinder (Napa part M2085, new), already "bench bled" the master. Got them all pretty and installed today, waiting on my new Stainless brake lines (Wednesday) and sent my proportioning valve to White Post Restorations. Might not see the valve back for a few weeks but it is totally worth it to have the right part, repaired correctly, with a lifetime warranty... ��I'll keep you guys posted on how it goes. Thx again for all the help.

[dmjlambert]

Some people have trouble with stainless steel lines leaking at the connections. That is because the metal is extremely hard compared to steel or nicopp. A friend of mine replaced the brake tubing in his Mustang with stainless steel and he complained it was like a fountain. I told him about copper flare gaskets that I used on my fuel line, because they make the flare fitting seal very well without having to torque very hard on the fitting. He loves them like I do. If you have leaks, don't fret and over-tighten the fittings, just get some of these. I only know about the one size for my fuel line, but supposedly they come in various sizes.

[Kalums]

Originally Posted by dmjlambert

Some people have trouble with stainless steel lines leaking at the connections. That is because the metal is extremely hard compared to steel or nicopp. A friend of mine replaced the brake tubing in his Mustang with stainless steel and he complained it was like a fountain. I told him about copper flare gaskets that I used on my fuel line, because they make the flare fitting seal very well without having to torque very hard on the fitting. He loves them like I do. If you have leaks, don't fret and over-tighten the fittings, just get some of these. I only know about the one size for my fuel line, but supposedly they come in various sizes.

SWEET! Thanks for the heads up.

[Kalums]

Ok gentleman, I've got my proportioning valve back from White Post (my wallet is definitely lighter, but it was my choice)... I've got new lines from the MC to the PV and from the PV to the "split" (front) and intermediate(rear) I've also got a new rubber hose with "t" from the intermediate line to the axle lines. I bench bled the master and PV then assembled everything. I BLED LINES FOR 2 FREAKIN HOURS... I've got no leaks and I've got what sounds like air still in the lines (in the back) and no rear drum activation... I bled with a crappy amazon vacuum bleeder and the 2 man method (1 pumping the pedal an 1 working the bleeder screw(s)... What am I doing wrong?? I'm ready to pull out my hair and commit Hari Kari... PLEASE HELP BEFORE I SET THIS THING ON FIRE AND PUSH IT IN TO A DITCH....

[Accelo]

I went through two aftermarket proportioning valves before I got one that didn't leak. Best of luck. There are rebuilders for the proportioning valves out there, but I don't know about turnaround times.
Cheers

[Kalums]

Originally Posted by Accelo

I went through two aftermarket proportioning valves before I got one that didn't leak. Best of luck. There are rebuilders for the proportioning valves out there, but I don't know about turnaround times.
Cheers

I got my proportioning valve rebuilt (original cast iron one) by White Post Restorations, I got it back last Saturday... My brain hurts and I can't figure out why I still have air after trying 2 different methods to bleed it.

[dmjlambert]

The only thing I can think of is air is entering into the lines some way. A crack in a line or bad connection maybe? I prefer one man bleeder method, chapstick on the threads of the bleeder screw, clear hose from bleeder screw with end submerged in a small bottle such as a spice bottle sitting in a coffee can. Pump brake pedal slowly but don't let the pedal go all the way to the floor. I put my left foot under the pedal so it blocks going to the floor. Repeat 10 or 20 times and check the clear hose and amount of fluid you've pumped. Keep master cylinder topped off with fluid and lid closed.

You mentioned so many things and I got lost. What do you have left that came with the truck, since the truck came to you with no working rear brakes? There's a lot of stuff in the brake system, and unfortunately some stuff may come new and bad. So there's old cracked and worn out or incorrect parts, and new bad parts, and then there's good stuff. I don't know how to test each item, but I would imagine there are methods to test each item.

I have a real mechanic I can take my truck to who sometimes bails me out when I can't figure it out.

I suppose a relatively cheap way to test would be to get a couple rolls of nicop tubing and tubing nuts and adapters, bender and flaring tool, and install temporary lines directly from the master cylinder to one of the front caliper hoses, and directly from the master cylinder to one rear cylinder. See if you can get a brake on the front and a brake on the back to actuate. Then keep cutting, bending, flaring, and introducing more parts. Somebody with more knowledge than me will probably have a better idea.

Sorry you're having such troubles. Pick only one, pull hair, hari kari, fire, ditch. Been there. Although my problems are most often looking for 4 hours for something I set down 30 seconds ago...

[Kalums]

Originally Posted by dmjlambert

The only thing I can think of is air is entering into the lines some way. A crack in a line or bad connection maybe? I prefer one man bleeder method, chapstick on the threads of the bleeder screw, clear hose from bleeder screw with end submerged in a small bottle such as a spice bottle sitting in a coffee can. Pump brake pedal slowly but don't let the pedal go all the way to the floor. I put my left foot under the pedal so it blocks going to the floor. Repeat 10 or 20 times and check the clear hose and amount of fluid you've pumped. Keep master cylinder topped off with fluid and lid closed.

You mentioned so many things and I got lost. What do you have left that came with the truck, since the truck came to you with no working rear brakes? There's a lot of stuff in the brake system, and unfortunately some stuff may come new and bad. So there's old cracked and worn out or incorrect parts, and new bad parts, and then there's good stuff. I don't know how to test each item, but I would imagine there are methods to test each item.

I have a real mechanic I can take my truck to who sometimes bails me out when I can't figure it out.

I suppose a relatively cheap way to test would be to get a couple rolls of nicop tubing and tubing nuts and adapters, bender and flaring tool, and install temporary lines directly from the master cylinder to one of the front caliper hoses, and directly from the master cylinder to one rear cylinder. See if you can get a brake on the front and a brake on the back to actuate. Then keep cutting, bending, flaring, and introducing more parts. Somebody with more knowledge than me will probably have a better idea.

Sorry you're having such troubles. Pick only one, pull hair, hari kari, fire, ditch. Been there. Although my problems are most often looking for 4 hours for something I set down 30 seconds ago...

Thank you for the encouragement, I've got no leaks I can find anywhere and I've tried everything I can think of. I will be going bit by bit through the system in the next few weeks. Right now I'm just very frustrated and befuddled... I've never had a vehicle that so many "maintenance" items were either purposefully broken or completely ignored, that is not a mindset I understand in the slightest.

[Kalums]

Well... Got an update for everyone..... Found "the leak". BOTH the brand new wheel cylinders were leaking, but also holding the fluid inside the outer rubber gaskets *rolls eyes*I've never seen that before, much less heard of it happening. When I vacuum bled the system it was pulling air past the pistons and seals, but wouldn't build enough pressure to push brake fluid past the outer seal into the brake/drum area. So Napa is replacing both wheel cylinders in the morning (of course I get to do the labor and all new seals on my full float axle *facepalm*.... Thx for the help everyone, hopefully this will fix it, gonna do Speedi-sleeves on the spindles while I'm at it. 👍