...or get air in my HCU? Just finished pressure-bleeding the brakes on my '99 (with ABS, obviously) - just replaced rotors and pads, used Centric "premium" rotors and Performance Friction "Carbon Metallic" pads. Nothing seemed out of the ordinary other than it seemed to me that the fluid was flowing awful slowly through the bleeder screws (had bleeder pumped up to about 15 PSI.) Brakes worked fine before although they required what I thought was a lot of leg to stop the vehicle, but I figured that was a) because XJs apparently have notoriously poor brakes and b) who knows what pads were on there before? Well now I just finished bleeding and took a couple laps around the neighborhood stopping hard a few times from about 30 MPH or so to bed the pads in. I still can't lock the brakes at 30 MPH (cool, dry) even though I can easily spin the tires in 2WD if there's only a little water on the ground. The pedal feels squishier than it did before as well, even though the only time that I opened the bleeders was to press the pistons back into the calipers. (I've always been told that if you have ABS you shouldn't ever push brake fluid back towards the MC to avoid gunking up the HCU.) The brakes felt pretty awful on a test drive last night, so I bled them tonight, they might feel slightly better or it might be my imagination.

I'm tempted to take it to a shop and have them rebleed with a scan tool to rule that out, but did I screw up by getting the PF pads? Upon searching it seems that the only pads that are really well regarded for XJs are the EBC Yellows and "Black Magic" but both are around $130 a set...?

I'm also wondering if I need new hoses - when using a pressure bleeder on an XJ, if you open the bleeders wide, do you get a real forceful stream or just a dribble?

opinions?

 

It does sound like you still have air in the system. When you bleed the breaks did you bleed them in the correct order? When bleeding your breaks you need to start with the passenger rear, then the drivers side rear, passenger side front. then the drivers front. this is the correct order to bleed the breaks system.
Hope this helps.
Good luck.

 

yes I did... done plenty of brake jobs before but this is my first vehicle with ABS (that I've actually worked on myself that is) it seemed like the fluid was flowing awful slowly when I did bleed though, on one of my old Studes if I pumped it up to 15 PSI it would fill a 20 oz. soda bottle in a minute or two (I always use a hose on the bleeder draining into a container so as to keep things neat,) this one took a lot longer... is there a trick I'm missing, or does that point to a restriction somewhere? Brakes don't seem to drag though like you'd expect if hoses were bad.

 

did you change the calipers by chance?

you should get a good steady stream out of the bleeders.

 

I think there must be a reason for the 'take the abs work to the dealer' caution in the manual. I don't know why a scanner would be needed, but I don't know about abs.

 

No, didn't change anything but pads and rotors. The reason for the scan tool is to get the air out of the working bits of the hcu. I was hoping someone would say I needed to zip tie something on a prop valve or something but chiltons is silent. I think there is a flow restriction somewhere but I don't want to mess with it w/o having DRB III. I also have a good enough pedal I think it should stop better than it does... And I figured new pads/rotors should give an improvement in braking, it feels worse than it did with the old worn out parts...

 

First, you changes the pads wrong. Via the pushing the piston back. NEVER open the bleeder screw unless you are purposely bleeding the system.

All you ever have to do, abs and non abs systems is to slowly push the piston back in until it seats, done. You will not get "gunk" in the system doing this.

After all is said and done when you go to press the brakes for the first time, pump half way, engine off until the pedal goes hard.

 

X2 A Jeeper. Def NEVER open bleeders except to bleed. I have at work run into instances of ignition needing to be on. Always seems to b Chrysler products. As matter of fact I even remember some having to b running while bleeding. Have u tried either while bleeding? When I get to work I'll look up factory procedure. Some abs systems do REQUIRE DRB

 

I tried bleeding w/ engine off, key off - chilton didn't say I needed to do anything else, still looking for a good deal on FSM. It's a 99 4.0, AW4, 4WD, ABS