About 2 years ago, I changed out my front rubber brake lines, replaced with replacement rubber brake lines. No leaks or issues. I'm starting with this, because I'm fairly sure the issue is NOT the lines. That said...

I am currently finishing up an LS1 front swap on my Formula. New Powerston calipers. When I bleed with the car turned off, I see no fluid leaks. Builds up pressure, firm brake pedal, no red "brake" warning light lit on the dash.

As soon as I turn the car on, in park, and press on the brakes a few times, I see leaks on both fronts.

I'm at wits end. I've taken the banjo bolts off numerout times, each time with new washers. Torqued to 110 inch-pounds. I even found an old thread, where Sofa suggested using two crush washers between the caliper and the brakeline (3 washers total per caliper)
https://www.thirdgen.org/forums/brak...iU#post4998618
Honestly, the 3-washer method is the closest I've come to no leaks. But some leaks is just not acceptable for obvious reasons.

I've done caliper swaps countless times in the past, and never had such problems.

Am I missing something?

 

How is the sealing surface on the caliper. I got some rebuilt ones once from a chain store and the surface was all chewed up from then using steel shot to clean them

 

Looked fine to me. I did hit it with a tiny wire brush during one of the removals, thinking maybe there was a small burr or something. But same result.

 

Check that the banjo on the end of the line is sitting flush to the caliper. Sometimes it rests on a protrusion or such and it rocks it a little. This may be why the three washer solution helps with the leaks.

If the crush washers are copper you can make them soft as butter. Heat them with a propane torch or on a gas stove top to dull red, then dunk into water. This will help in getting a good seal.

RBob.

 

Ok thanks, I'll give it a try. I have more crush washers coming; should arrive by this weekend.

Also, any opinions about stat-o-seal washers?
https://www.ebay.com/itm/27406833976...8AAOSwfl1gPK~j

 

I'm not a fan of the stat-o-seal washers. For two reasons: no pressure rating, and no real information on the sealing material. For the former, brakes run at high pressure, easily up to 1200 psi.

For the latter, is the 'synthetic rubber' compatible with brake fluid? I looked at them for fuel fitting seals, but skipped them due to this. Didn't know if the rubber was compatible with fuel. So actually went with a copper crush washer (annealed).

That being said, I would probably use them for water/coolant sealing. Or possibly a non-pressurized oil passage to prevent seepage.

RBob.

 

Ive never used a torque wrench on banjo bolts. Maybe try tightening them more so they seat the washers 110 inch pounds isnt that tight imo.

 

I wanted to follow-up, and say that I did finally get things working (so far, so good, anyway). I do appreciate the advice given.

I did a few things differently this time. I'm not sure which exactly was the issue, or maybe it was a combination of several. Here are some suggestions, for anyone who finds this thread in the future. (I hate running into threads that just sorta die, with no solution)

1. I replaced the hoses. I'm pretty sure this was not the issue, as the other hoses were less than 2 years old. But hoses are cheap.
2. On the hose, I removed the thick foam insulation at the end. I used a set of dike cutters, to make sure I didn't nick the hose. I think this insulation is probably thick enough, to throw things off.
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3. The hose end has two distinct ends. You obviously need to use the end that is totally flat towards the caliper, and not the side with the small step. I had done this correctly, but wanted to throw it in, anyway
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4. I used RBob's suggestion, and heated up the crush washers with a torch, before use. Again, not sure it made any difference, but something fixed it.
5. If I had to guess, I think the issue was that the line was just too tight/short, between the center hanger, and the caliper. When I hooked things up before, the hose was already hooked up to the hardline, and hanging. I mounted the calipers, then attached the banjo. That method did not work, for me. The line was REALLY tight.
   1. This time, with the new hoses, I did reverse order. I hooked up the calipers, off the car, so I could see what I was doing. Then I mounted the caliper. Next I removed the bracket hanger that hooks to the middle of the hose. The hanger was removed from the car, when I ran the hose through said bracket. Once the hose was in place, I added the clip, and mounted the hanger to the car. Finally, I mounted the end of the hose, and hooked it up to the hardline.

It's really tight. But it seems to be working. There is another hose part number, that is 2" longer. I assume that is for the 1LE front calipers. I'm not sure it that part would fit these LS brakes, or not. Those hoses are only like $2 more.

 

I swapped Ls1 brakes on my 94 and really had to crank them down harder than I felt safe so they would not leak. They held. Awesome mod.

 

Okay so I know this could be considered a thread brought back from the dead, but just in case someone else runs into this same issue it could be useful info.

When I installed my LS1 front brake upgrade, I ran into the same issue where the brake hose was too short on the caliper side and when turning the spindle lock to lock it would try to stretch the hose.
All you need to do to fix this problem is spray a little bit of WD-40 on the hose where the bracket attaches it to the strut. Give it a bit of a tug to get the hose to move and thanks to the WD-40 it'll allow you to easily move the hose where it needs to be to have enough slack on both sides of the bracket.