Hi All,
I'm new to this site (and a new, first time FJ 40 owner, so please forgive me if this topic has been covered. I can't find any threads that solve the issue I'm having). You guys are so helpful with all the information I've read about other issues while I"m trying to resurrect it! Thanks for all your postings.
I bought my first FJ40 about 1.5 months ago. The previous owner gutted the wiring (engine wiring and all), swapped in Dana 44's from a Jeep Wagoneer, and let it sit for 4 years in his yard. It's got a Chevy 350, with SM465 tranny and stock transfer case. The Dana 44's have stock disc's in the front, and drums in the rear. The PO also installed a Wagoneer proportioning valve (think it's actually a stock or boneyard find, as it's somewhat rusty). I've got the wiring done (don't let EZ wiring fool you - it's not THAT easy), the engine running strong, and got all the brake lines made and installed. With the axle swap, at the same time, PO swapped in a power brake booster and master cylinder from a 1985 FJ60. Once I connected everything up, I figured out the master was shot so I replaced it with a new one. I could only get very little pressure with the new MC, but enough to actually stop it pretty well so headed out to my tire shop to get new tires and wheels put on (35x12.5 BFG KM2 MT's on Flat Black Pro Comp Rockcrawler wheels - I'm dying to get this thing back tomorrow). On the way, my front calipers bound up and I had to pull over (smoking brakes, the hole deal). I had it towed to the shop, and they de-pressurized once they cooled. The shop can't get any pressure on the peddle at this point. I've worked on these brakes for about 1 full week before driving it, and am somewhat at a loss as I don't have good knowledge of a pieced together system like this. My shop can keep working on them, but at this point I'm gonna pick it up and put the money into new brake parts. Anyone have any ideas what could be going on?
Couple other questions I have:
1. Can I replace the proportioning valve a Chevy valve? They look identical to a Wagoneer, with the same line size connectors, but are more readily available (can get one off Amazon tomorrow and have it by Saturday). Also, do they need to be bled? I'm wondering if that is part of the problem.
2. Will the '85 master/power booster work with this application? I'm not sure it's pushing enough volume to pressurize the brakes, and it seems like the push rod engages the master cylinder piston slightly when it's mounted (I've adjusted the piston depth at the master and brake pedal arm but it still sticks out slightly too far). Should I go back to a stock FJ40 MC? I'm getting a lot of fluid from all 4 wheels when I bleed them.
3. I don't know anything about brake boosters - could the booster have a leak somewhere, and be putting suction on the MC causing it to lock up the brakes? It seems weird that it starts binding up as I'm driving (and the engine is running, pulling suction on the booster the hole time). I did notice the peddle was getting firmer before I stopped driving it when the brakes bound up (BTW, it was the front discs only - nothing, not even any heat at the rear drums).
4. If I go back to a stock, manual FJ40 MC, will it work with disc/drums?
Sorry to be so long winded. Thanks for any help you can give me!
I'm new to this site (and a new, first time FJ 40 owner, so please forgive me if this topic has been covered. I can't find any threads that solve the issue I'm having). You guys are so helpful with all the information I've read about other issues while I"m trying to resurrect it! Thanks for all your postings.
I bought my first FJ40 about 1.5 months ago. The previous owner gutted the wiring (engine wiring and all), swapped in Dana 44's from a Jeep Wagoneer, and let it sit for 4 years in his yard. It's got a Chevy 350, with SM465 tranny and stock transfer case. The Dana 44's have stock disc's in the front, and drums in the rear. The PO also installed a Wagoneer proportioning valve (think it's actually a stock or boneyard find, as it's somewhat rusty). I've got the wiring done (don't let EZ wiring fool you - it's not THAT easy), the engine running strong, and got all the brake lines made and installed. With the axle swap, at the same time, PO swapped in a power brake booster and master cylinder from a 1985 FJ60. Once I connected everything up, I figured out the master was shot so I replaced it with a new one. I could only get very little pressure with the new MC, but enough to actually stop it pretty well so headed out to my tire shop to get new tires and wheels put on (35x12.5 BFG KM2 MT's on Flat Black Pro Comp Rockcrawler wheels - I'm dying to get this thing back tomorrow). On the way, my front calipers bound up and I had to pull over (smoking brakes, the hole deal). I had it towed to the shop, and they de-pressurized once they cooled. The shop can't get any pressure on the peddle at this point. I've worked on these brakes for about 1 full week before driving it, and am somewhat at a loss as I don't have good knowledge of a pieced together system like this. My shop can keep working on them, but at this point I'm gonna pick it up and put the money into new brake parts. Anyone have any ideas what could be going on?
Couple other questions I have:
1. Can I replace the proportioning valve a Chevy valve? They look identical to a Wagoneer, with the same line size connectors, but are more readily available (can get one off Amazon tomorrow and have it by Saturday). Also, do they need to be bled? I'm wondering if that is part of the problem.
2. Will the '85 master/power booster work with this application? I'm not sure it's pushing enough volume to pressurize the brakes, and it seems like the push rod engages the master cylinder piston slightly when it's mounted (I've adjusted the piston depth at the master and brake pedal arm but it still sticks out slightly too far). Should I go back to a stock FJ40 MC? I'm getting a lot of fluid from all 4 wheels when I bleed them.
3. I don't know anything about brake boosters - could the booster have a leak somewhere, and be putting suction on the MC causing it to lock up the brakes? It seems weird that it starts binding up as I'm driving (and the engine is running, pulling suction on the booster the hole time). I did notice the peddle was getting firmer before I stopped driving it when the brakes bound up (BTW, it was the front discs only - nothing, not even any heat at the rear drums).
4. If I go back to a stock, manual FJ40 MC, will it work with disc/drums?
Sorry to be so long winded. Thanks for any help you can give me!