jaekl Posted June 21, 2007 Share Posted June 21, 2007 Because of a brake line leak, I'm involved with the height sensing valve. It turns out the leak was from a rusty brake line. After replacing the rusty lines the way they were, the rear brakes get no fluid. Now I'm thinking that the lines to the valve were switched by the PO. I've found a factory diagram and it looks different. Can someone confirm which port of the height sensing valve goes to the T that feeds the wheel cylinders, top or the side one? The other port is fed by the regular service line from the combo valve. Link to comment Share on other sites More sharing options...
Tracker Posted June 21, 2007 Share Posted June 21, 2007 Watch- This forum tends to hate that valve. They'll tell you to junk it and do everything but fix it right. Our MJ isn't here right now or I'd go look at how the lines are ran. Our rear brakes work great. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted June 21, 2007 Share Posted June 21, 2007 Watch- This forum tends to hate that valve. They'll tell you to junk it and do everything but fix it right. Our MJ isn't here right now or I'd go look at how the lines are ran. Our rear brakes work great. agreed, the suitable upgrade is to replace it with a xj prop valve (located at the brake booster). Eagle posted up an exact way to set it up recently, but I'm sorry...i don't know how it's supposed to be hooked up. the FIRST thing I do to all of my comanches that are getting a lift or being used regularly, is just chop out the rear valve, known as the proportioning valve. putting one from an xj in ensures that it "works", and usually brake lines need replacing anyways. I believe that you may have it hooked up correctly and just didn't bleed it properly...there's a wicked long bleeding procedure for the prop. valve. again, ask Eagle Link to comment Share on other sites More sharing options...
pingpong Posted June 21, 2007 Share Posted June 21, 2007 Its not that we hate it... it is that it doesnt function right once you lift it, and most of the time the lines rust in 2 behind the gas tank. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 22, 2007 Share Posted June 22, 2007 Watch- This forum tends to hate that valve. They'll tell you to junk it and do everything but fix it right. Our MJ isn't here right now or I'd go look at how the lines are ran. Our rear brakes work great. Got that right. RIP IT OUT! Don't fix it, adjust it, or alter it, just RIP IT OUT!. Mine works great, always has, and when I put in my little 2-1/2" lift, I just entended the frame-to-arm operating rod the same length as my lift, and it still works great. 'Course if it ever gets frozen inop from rust, which is why I expect everyone hates it, maybe then I'll RIP IT OUT and do the bypass w. the brake lines. But it aint broke, and I aint fixin it - yet :chillin: Link to comment Share on other sites More sharing options...
Tracker Posted June 22, 2007 Share Posted June 22, 2007 Maybe we're just lucky to have one that works right, and to live in the land of no rust. 8) When we went SOA, our kit (also not forum approved) had a bracket to relocate the valve linkage. It all still works great. Recently, we had a bit of a par-tay and had to haul 600 pounds of ice in the MJ. It made a noticeable difference in braking. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted June 22, 2007 Share Posted June 22, 2007 Maybe we're just lucky to have one that works right, and to live in the land of no rust. 8) When we went SOA, our kit (also not forum approved) had a bracket to relocate the valve linkage. It all still works great. Recently, we had a bit of a par-tay and had to haul 600 pounds of ice in the MJ. It made a noticeable difference in braking. it's not that it isn't forum-approved. innovation is key. it's simply fact that the comanche lines rust and that in that situation and most situations, it's completely un-productive to try to re-use it if it's bad and needs to be torn apart... Link to comment Share on other sites More sharing options...
jaekl Posted June 22, 2007 Author Share Posted June 22, 2007 Okay, okay. I realize I'm about to pull it out. I just want to confirm where the lines are suppose to go. Can anyone that has a working valve tell me where the line from the T go? The top port or the side port? I think it should be the top port. Link to comment Share on other sites More sharing options...
jaekl Posted June 22, 2007 Author Share Posted June 22, 2007 Sorry, I think the line to the T should come from the side port not the top. Link to comment Share on other sites More sharing options...
Pete M Posted June 22, 2007 Share Posted June 22, 2007 If you're going to rip it out, you can either simply put a T-fitting in it's place or (and this is what I did) run a single line from the combo valve in the engine bay back to the rear axle. It should originate from the side port and then you plug the bottom one: Link to comment Share on other sites More sharing options...
Tracker Posted June 22, 2007 Share Posted June 22, 2007 The line from the top of the load sensing valve goes to a "T"; one side which goes to the rear axle and the other side goes forward. Link to comment Share on other sites More sharing options...
1986Comanche Posted June 22, 2007 Share Posted June 22, 2007 Because of a brake line leak, I'm involved with the height sensing valve. It turns out the leak was from a rusty brake line. After replacing the rusty lines the way they were, the rear brakes get no fluid. Now I'm thinking that the lines to the valve were switched by the PO. I've found a factory diagram and it looks different. Can someone confirm which port of the height sensing valve goes to the T that feeds the wheel cylinders, top or the side one? The other port is fed by the regular service line from the combo valve. I just looked at my 1986 Comanche and the line comes out of the top port of the height sensing valve and goes to the T. Then a line goes from the T to the rear brake hose. Link to comment Share on other sites More sharing options...
jaekl Posted June 25, 2007 Author Share Posted June 25, 2007 Thanks for the line confirmation. I was plumbed right. Mine problem was I had it at the wrong position. Didn't have rear brakes for a few days, but pressure built up but didn't release. Found procedure to set the valve. Don't have the tool but put the flat at about 4:30 and is working. Kinda strange to set the flat in such a odd orientation. Pulled the combo valve out of the parts car just in case. Sure was full of gunk. Not a whole lot of room to get to it with the 4.0 liter manifold right there. Also had a problem on my 86 XJ. Just wouldn't start. Learned about unplugging the CPS. (I grew up with points) Plugged it back in and fired right up. Will I have to do that in another 21 years or does it mean the sensor is going? Sorry for the hyjack, tough Friday but the Jeeps are back. Link to comment Share on other sites More sharing options...
Eagle Posted June 25, 2007 Share Posted June 25, 2007 Its not that we hate it... it is that it doesnt function right once you lift it, and most of the time the lines rust in 2 behind the gas tank. Add to that that one of us (me) doesn't trust them, since the one in my '88 blew out in a panic stop. If the bladders or glands or whatever are subject to age deterioration, I don't want it back there. Link to comment Share on other sites More sharing options...
Eagle Posted June 25, 2007 Share Posted June 25, 2007 Watch- This forum tends to hate that valve. They'll tell you to junk it and do everything but fix it right. How do you "fix it right" after it explodes? How do you "fix it right" when the factory service manual tells you it needs NEW parts each time you adjust it, and those parts are not available? Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 25, 2007 Share Posted June 25, 2007 There are a couple of articles floating around detailing replacment of the obsolete MJ load sensing valve with a similar unit from a Toyota Tacoma or Nissan truck. An old retired Jeep dealership mechanic in town also told me that he had changed several of them out while at the dealership. He said the plumbing was the same and it was an easy install. If mine ever craps out, that's probably what I will do. Link to comment Share on other sites More sharing options...
Imjustheretogethelp Posted September 22, 2019 Share Posted September 22, 2019 Ok I'm having an issue with this and I don't know if this chats dead or not but what I did was just ripped out the rod that went to the axel and that was it. Is there anything wrong with that? Link to comment Share on other sites More sharing options...
eaglescout526 Posted September 22, 2019 Share Posted September 22, 2019 58 minutes ago, Imjustheretogethelp said: Ok I'm having an issue with this and I don't know if this chats dead or not but what I did was just ripped out the rod that went to the axel and that was it. Is there anything wrong with that? No. But stopping with a load in your bed will require you to brake earlier than what you would. You can use hornbrods fix for the rod and clips or you can delete it. Link to comment Share on other sites More sharing options...
Eagle Posted September 23, 2019 Share Posted September 23, 2019 10 hours ago, Imjustheretogethelp said: Ok I'm having an issue with this and I don't know if this chats dead or not but what I did was just ripped out the rod that went to the axel and that was it. Is there anything wrong with that? Well, aside from the fact that you now don't have a functional rear brake proportioning valve, and you have no idea if your rear brakes are now fully on, fully off, or somewhere in between ... no, nothing wrong at all. Why did you remove the actuating rod? Doing that can't possibly help anything, and in most cases will make any issues you have worse. Link to comment Share on other sites More sharing options...
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