Teraflex Delta Brakes

Sorry this is so long. I had an off-road shop install some Teraflex Delta Brakes on my 2019 JLUR in preparation for getting some 39" KM3's for it. I'll keep the shops name out of this for now. After installing the brakes they said they didn't like the way they felt and kept it overnight. When I picked it up the next day they didn't feel great to me so I asked them if they had done the ABS bleed on them and they hadn't. I know they hadn't because my tazer was still married and you can't do the ABS bleed with it married. Anyway I took it back and they said they did the ABS bleed and then re-bled the brakes the traditional way. The brakes still didn't feel hard and would go down.

So I bought a scanner to do it myself. I bled them the regular way twice, ABS bled them twice, and then re-bled them twice the regular way again. This seemed to help a little so I went to Little Moab to try them out. The first steep hill I went up I couldn't make it. I hit the brakes and the pedal slowly sank to the floor and I slowly started to go backwards. Luckily it was very slow or I would have been in trouble. Since then I've bought a second scanner, ABS bled them twice again, and regular bled them 3-4 times.

Fast forward to today I swung into Les Schwab and they said it sounded like the Master Cylinder was bad. I read online if you get to aggressive with a brake bleed it can blow out the seals. Les Schwab doesn't do Master Cylinders so I googled who did Master Cylinders and Tunex came up so I ran down there. The guy said their diagnostic guys are only there Mon-Fri but said it could be the Master Cylinder. Their brake guy has been doing it for 40 years so I made an appointment to take it in on Monday morning to get it looked at.

Does this sound like it could be the Master Cylinder or is just a bunch of incompetent bleeders (including me)? It has 147,000 miles on it. Any other guesses?

I really need this done on Monday as it goes in on Tuesday and Wednesday for the lift and then I'm down in Moab for the rest of the week. Unless it gets fixed we'll take my wife's car down. It's a thing for her work. I get the tires the following week and go to EJS the weeks after that. I know I'm cutting it close on everything.

Thanks in advance!

Brake pedal slowly going to the floor, most likely a master cylinder.

It does sound like a master cylinder issue. If when they first started to bleed they let the pedal travel all the way down before it had any resistance that can damage the seals in the master. I always like to only let the pedal drop just past half pedal for the first few bleeds. Then when you get a decent pedal let it fully travel to the floor.

Thanks for the feedback guys! Hopefully Tunex comes to the same conclusion and replacing the master cylinder will make everything better. I would hate to spend that much on brakes and have them not work right.

If you can bleed your brakes, you can knock out a master cylinder. I've had master cylinders go out, but the pedal would go to the floor without enough resistance (you could feel the failed seal). Something like this sounds like a slowly failing seal in the master cylinder

I thought about doing it myself but with the time crunch and me needing my Jeep to go in Tuesday morning for the lift I decided to let the experts do it. It's nice to know that it's not terrible if the need arises in the future.

If you pump the brake pedal a few times does it build pressure and hold? We have done a few of these kits and never had an issue. I assume they didnt install the calipers upside down? I have seen that a handful times in my day.

It doesn't hold pressure if you pump the brakes. It does just fine for around town for stopping but if you push it hard, not crazy hard, when stopped at a stoplight they go down and pumping doesn't seem to have too much effect. I double checked they didn't install the back ones upside down but haven't visually checked the fronts. When I get it back from getting the lift on I'll double check the fronts. I'm going to take it in Monday to someone if you have any suggestions. I need it back by Wednesday if possible to finish up what needs to be done for EJS. I was thinking Master Autotech but I've never used them before. They're just fairly close to me.

Tunex just drove it around the block and said "they felt fine". So they were no help.

can you get it to Agility?

ID Bronco said:

can you get it to Agility?

Click to expand...

There is no way we could get to it before EJS though

That's going to be the problem with off-road shops I think 🤔