Bad day on brakes..........

[jammer1]

Take it one step at a time. Unscrew the brake line (from m/c) at proportionate valve. With cap off try to gravity bleed (take valve out of the equation). If given enough time and it doesn't bleed try pushing the brake pedal down (Block it down so it doesn't come up and draw air into the m/c). Sounds like you have one that's a pain in the ***. By the weekend I should be bleeding the CJ8 I'm building. Everything new. Not looking forward to it. On yours, if you can get it to bleed out of the m/c the rest should be a cake walk.

 

[jammer1]

One other thought do you have the brake lines coiled where they meet the m/c. If you do and their horizontal in the coils gravity bleeding won't work till you have that section of line going down (you would have mini traps to hold the air). Make the bend going down where the lines exit the m/c.

 

[Hedgehog]

Lumpy - The MC is an OMIX model for 1978 Disk/Drum system. The p-valve appears to be a GM model. The system is all married up with a bracket on the bottom of the MC holding the p-valve. Short lines (1 front brake and 1 rear brake) go from the MC to the p-valve, 3 lines go to the wheels (1 rear, 2 front). While it's not rocket science, it is a complicated arrangement with lines that need to be fairly close in both length and angle to make assembly even possible. At this point I'm not ready to take everything apart to get serial numbers. I'm not saying that it won't end up happening, it's just not yet that time.

jammer1 - The odd part is, the MC bench bleeds, even with the P-valve in the system. No apparent problem there. I've even blown out the front lines with air, no restriction there. I haven't done the rear though. Why? The front made quite the mess, but I should have done it anyway. The thing has been "gravity bleeding" since Monday night, no change in status.

Next step ..... A D.I.Y. reverse bleeder is ordered and on it's way. It's a fairly simple system that pushes fluid into the system from the wheel cylinder. Before I try it I'll blow out the rear brake lines too. If this doesn't work more drastic measures will be in order. Like possible parts replacement.

 

[Lumpy Grits]

Omix stuff, scares me.
Please check the hard lines to be sure there's no 'kinks' that could stop fluid flow.
Fingers crossed,
LG

 

[Hedgehog]

Yeah - I know about Omix, it was what my Jeep guy had available. He doesn't like'em either. No kinks in the front, air shoots through the lines with no real back pressure. I'll be blowing out the rear lines when I get the reverse bleeder going.

 

[jammer1]

I've never done one that has the proportionate valve just below the m/c (newer style's I've seen on ebay). As long as the lines don't twist upward than back down it should bleed. This spring I bleed my CJ8 (ground up build) with everything new and had no problem gravity bleeding it. Just took about 15 min to start dripping out the rear brake. Today I just replaced the proportionate valve on the CJ7 . Damn m/c was gravity bleeding on me (valve removed) the whole time after I loosened the lines (even with the cap on). If you have a extra cap and gasket you could drill a hole in the cap and epoxy a nipple on it (one on each side of cap). Connect a air tank or compressor with a regulator. Fill the m/c and let just enough air in to force the fluid down the line (not enough to empty the m/c. If you have a pump bug sprayer you could use that and put a quart of brake fluid in it. A home made version a power bleeder. I also purchased one (think off ebay) professionally made. Only problem is you go through a quart or two a bleeding. Wasn't worth wasting that much fluid for a once every 2 to 3 years.

 

[Hedgehog]

As promised, I hooked up the Air compressor and blew out both rear brake lines (1 goes into 2). Some residual fluid ended up in the glass jar at the wheel cylinder. The reverse bleeder is in, I'll pick it up tonight and try it tonight.

If this doesn't work I'm going back to my original plan. That is to go with the very large power brake booster, P-valve and MC. I probably should have stuck with that plan all along.

 

[Lumpy Grits]

Very best of luck
LG

 

[Hedgehog]

I'm tellin' yeah, I'm getting extremely itchy to get the CJ back on the road. Not working on it for a little while sounds mighty nice right now.

 

[HackFabrication]

Can you post a pic of the front brake calipers, both left and right?

 

[jammer1]

Hedghog, is the M/C a manual or power brake? This doesn't make sense, you should be able to remove the brake lines connected to the valve (lines going to the brakes) then the brake fluid should drain out of the m/c, through the valve and out onto the jeeps fender. Is it possible the m/c internals (ex. cups out of position blocking the exits of the m/c. If you disconnect the brake lines and press the brake pedal will it squirt the brake fluid out the the valve.
It may be me, but I find it a little hard to understand how you can bench bleed the m/c only to force the air you don't want in the m/c back up through the brake lines. All in fun, I wish I could give you something else. I have a sick feeling you have a problem with the m/c or the valve that may not be air related. Please keep us advised and don't give up.

 

[Neuner]

FWIW: I have never had much luck with a vacuum bleeder. I have seen vacuum bleeders 'trip' a p'valve because of psi drop in the brake line.
LG

Interesting. Never heard that before but good to know. I used one on my back brakes for the 1st time several months ago and worked well. Brakes and relationship with my wife improved since she didn't have to help.

 

[Hedgehog]

Saturday morning report. Along with a summary of what's been done....

MC bench bled several times....

Brake lines blown out with air...

Days attempting a conventional bleed...

Days attempting Vacuum bleed ...

Purchase of a reverse bleeder. I wanted to come in here with what would have amounted to a commercial for how wonderful a reverse bleeder is. The bleeder did work as advertised. I thought, "By golly this is going to work." After reverse bleeding it is said that you generally don't need to do anything else. So, I gentle pressed on the brake pedal, some resistance, good, a second press, less resistance ........ Then like every other try NOTHING!!!!!!!! I have taken another direction now. Like Grumpy has mentioned, Omix is a less than trusted company and I'm sure its the master cylinder that has let me down. The thing must be sucking air or something similar.

A new/old direction now. As mentioned before I already have a complete power assist unit the manufacturer calls an "All Shebang" system. I didn't want to use it because of a couple things. My first '80 CJ5 had a disk/drum brake system with no power assist and it worked well. The "All Shebang" is a great big thing, 19.5" long, inside the fire wall. I felt that there simply wasn't room enough for it, tightening headers, a V8, an air pump system, steering and changing spark plugs. But darn it, I know it's got quality components and it's paid for. So, I give up on the Omix MC and the "All Shebang" is in there now. I need some more brake lines, but it will be done today....................

Hack - I don't know what good a picture will be. The front brake has new disks, new calipers, new dust shields, new brake line hoses. Yes, it's the somewhat hated Jeep 1977 thick disk/caliper model. It should work. At least for a while.

Neuner - The vacuum bleeder did not work for me, but I have talked to someone that uses vacuum bleeding all the time and I've some different insight as to how to use it. He doesn't use the bleeder caps, he uses the needle. .... more later, I've got to go to the store.

 

[mriplaybass]

Saturday morning report. Along with a summary of what's been done....

MC bench bled several times....

Brake lines blown out with air...

Days attempting a conventional bleed...

Days attempting Vacuum bleed ...

Purchase of a reverse bleeder. I wanted to come in here with what would have amounted to a commercial for how wonderful a reverse bleeder is. The bleeder did work as advertised. I thought, "By golly this is going to work." After reverse bleeding it is said that you generally don't need to do anything else. So, I gentle pressed on the brake pedal, some resistance, good, a second press, less resistance ........ Then like every other try NOTHING!!!!!!!! I have taken another direction now. Like Grumpy has mentioned, Omix is a less than trusted company and I'm sure its the master cylinder that has let me down. The thing must be sucking air or something similar.

A new/old direction now. As mentioned before I already have a complete power assist unit the manufacturer calls an "All Shebang" system. I didn't want to use it because of a couple things. My first '80 CJ5 had a disk/drum brake system with no power assist and it worked well. The "All Shebang" is a great big thing, 19.5" long, inside the fire wall. I felt that there simply wasn't room enough for it, tightening headers, a V8, an air pump system, steering and changing spark plugs. But darn it, I know it's got quality components and it's paid for. So, I give up on the Omix MC and the "All Shebang" is in there now. I need some more brake lines, but it will be done today....................

Hack - I don't know what good a picture will be. The front brake has new disks, new calipers, new dust shields, new brake line hoses. Yes, it's the somewhat hated Jeep 1977 thick disk/caliper model. It should work. At least for a while.

Neuner - The vacuum bleeder did not work for me, but I have talked to someone that uses vacuum bleeding all the time and I've some different insight as to how to use it. He doesn't use the bleeder caps, he uses the needle. .... more later, I've got to go to the store.

Geezz Hedge! I think we should relinquish the name of our CJ7 project (They're coming to take me away ah ha) to you! I think you are right, good ol OMIX! Sounds like the fluid is just leaking past the piston in the MC. I like you're idea of choosing a much less frustrating alternative. Good luck!

 

[jammer1]

Like I said I have a sick feeling you have a bad m/c. If the cups are out of position a little and are covering the openings going out it would stop the gravity bleed. I had one (Vanco unit) that had blow by past the cups. I asked Vanco sent me a rebuild kit that I had my mechanic use. Still had problem. Went on ebay and got a new m/c and knock-on-wood still works perfect. Must have been something in the bore. Is the m/c that you had before good enough to try as a test? Why don't you get a setup off ebay. Here's one a fellow member on CJ8 .com got and did a write up on Brake upgrade #3.... Similar to what I got from Vanco (minus the proportionate valve).

 

[Hedgehog]

jammer - The one I'm going with now is a new one that is big enough for me to attempt going in another direction ... at first. I've got it about 2/3rds installed. Had to make a new set of brake lines from the old P-valve was on the frame up to where it is now. Then drilled some new holes, moved some stuff out of the way (air pump injection valve), had trouble properly lining up a brass fitting I couldn't see well enough. The last two fittings will be done this morning.

I sorta did Omix a bad favor, the MC actually was a Crown part. Really two peas in a pod as far as over all quality is concerned. I was going to take it out in the desert, I haven't shot my M1 Garand in a while, revenge can be sweet. Unfortunately my Jeep guy at Willys Works wants it back. He wouldn't take cash for some parts I got yesterday insisting that he owed ME money. I explained the shooting thing, but he insisted. For those of you who get all twisted up about the shooting the MC in he desert, I don't leave trash in the desert and leave nothing bet foot prints behind.

Bass - Early on I called my CJ "The Witch" due to her color looking like the "Wicked Witch of the West". She's just earning her name is all.

As I'm sure you know for a project like this one, an entire front end rebuild and swap along with installing a Tru-lock carrier can got one of two ways. As far as brakes are concerned they either go on perfectly or are a complete nightmare. All in all this has been good, until now. Hopefully today will make up for it though.

 

[Lumpy Grits]

Best thoughts for you, to have a good day wrench'n.
LG

 

[Petescj]

Best thoughts for you, to have a good day wrench'n.
LG

What Lumpy said. You need some good luck to come your way. Hope you get it beat today.

 

[Woolyworm]

Chuckling at the witch comment good luck. I'd still find something to nail with the M1.


Wooly

 

[jammer1]

Sounds like you have a good jeep guybe watching with fingers crossed