Brake Booster issue after adding a mod
09-16-2009, 03:23 PM
#1
JK Freak
Thread Starter
Brake Booster issue after adding a mod
I posted this in the thread of WOL's write-up (http://project-jk.com/jeep-jk-write-...ation-write-up) for the ARB compressor installation, but thought I might get more answers for help with a new thread.
I added the ARB compressor with the bracket from Northridge 4x4 a couple of nights ago:
I need some help here.
Got my kit from Northridge 4x4 and finally got it installed the other night with great ease with WOL's writeup.
When doing step 2: "2. Carefully pull the master cylinder forward and off the mounting studs and then then slip the ARB compressor mounting bracket on to them as shown in this pic."
I heard a bit of a loss of vacuum from the brake booster, didn't think too much of it at the time, put it all back together, finished the install, now my brakes act a little funny. They feel "safe" and stop me fully everytime, but are different feeling from what they were before.
When on a slow brake coming to a full stop, everytime the engine downshifts, the brake pedal pushes back against my foot and the brakes let off for about 1 second or less, then they act normal.
I did a couple of tests I found online: 1. Engine off, depress brakes multiple times then hold in pedal and start engine, pedal goes in appropriatly then. 2. then i start engine, depress brakes several times, then hold brake pedal down, then turn off engine and I guess the pedal should stay still, but no, it pushes back up at my foot.
No brake light on in the dash. No warning lights anywhere.
I don't know alot about brakes and am worried I have totally screwed up. I need to check all vacuum lines tonight at home and make sure I didn't loosen one up during the install but I don't think I did.
Any ideas on what to do??
I added the ARB compressor with the bracket from Northridge 4x4 a couple of nights ago:
I need some help here.
Got my kit from Northridge 4x4 and finally got it installed the other night with great ease with WOL's writeup.
When doing step 2: "2. Carefully pull the master cylinder forward and off the mounting studs and then then slip the ARB compressor mounting bracket on to them as shown in this pic."
I heard a bit of a loss of vacuum from the brake booster, didn't think too much of it at the time, put it all back together, finished the install, now my brakes act a little funny. They feel "safe" and stop me fully everytime, but are different feeling from what they were before.
When on a slow brake coming to a full stop, everytime the engine downshifts, the brake pedal pushes back against my foot and the brakes let off for about 1 second or less, then they act normal.
I did a couple of tests I found online: 1. Engine off, depress brakes multiple times then hold in pedal and start engine, pedal goes in appropriatly then. 2. then i start engine, depress brakes several times, then hold brake pedal down, then turn off engine and I guess the pedal should stay still, but no, it pushes back up at my foot.
No brake light on in the dash. No warning lights anywhere.
I don't know alot about brakes and am worried I have totally screwed up. I need to check all vacuum lines tonight at home and make sure I didn't loosen one up during the install but I don't think I did.
Any ideas on what to do??
09-16-2009, 07:52 PM
#2
JK Super Freak
I would go a head and bleed them. Also, how is the brake tied to the master cylinder. Is it a push pull rod or a cable. Of it is a push pull rod, you may need to make some adjustments.
09-17-2009, 09:24 AM
#5
JK Super Freak
True, it can be a vacum leak... I changed the one I had on my miata and I had to make adjustments to the push rod to get the feel right. It was more an issue of when it would engage.
10-09-2009, 05:18 PM
#6
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I figured it out!
You probably solved your problem by now, but here it is anyway.
Background: I had the same problem. I pulled on master cylinder, there was a hiss, then started having vacuum leak problems, so i was looking at your thread to see if there was a solution...
I browsed through a shop manual and figured it out.
Answer: O-RING!
there is an o-ring between your master cylinder and the power boost (black drum thing). When we pulled on the master cylinder, the vacuum that was inside the power booster sucked in the oring. I pulled the master cylinder, and looked inside the power booster. there is a spring looking thing, and somewhere in there should be a black o-ring the size of the opening. Stick your finger in and pull it out!
slide this oring around the outside of the master cylinder, all the way towards the cylinder body. when you put it back and tighten, the o-ring will sit nicely between the master cylinder and the booster, creating a seal. Problem solved. no need to bleed brakes because you didn't actually let any air in.
it's 9pm here, dark out, was working on this all night... tired.
good luck!
Background: I had the same problem. I pulled on master cylinder, there was a hiss, then started having vacuum leak problems, so i was looking at your thread to see if there was a solution...
I browsed through a shop manual and figured it out.
Answer: O-RING!
there is an o-ring between your master cylinder and the power boost (black drum thing). When we pulled on the master cylinder, the vacuum that was inside the power booster sucked in the oring. I pulled the master cylinder, and looked inside the power booster. there is a spring looking thing, and somewhere in there should be a black o-ring the size of the opening. Stick your finger in and pull it out!
slide this oring around the outside of the master cylinder, all the way towards the cylinder body. when you put it back and tighten, the o-ring will sit nicely between the master cylinder and the booster, creating a seal. Problem solved. no need to bleed brakes because you didn't actually let any air in.
it's 9pm here, dark out, was working on this all night... tired.
good luck!
10-09-2009, 11:55 PM
#7
JK Jedi
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You probably solved your problem by now, but here it is anyway.
Background: I had the same problem. I pulled on master cylinder, there was a hiss, then started having vacuum leak problems, so i was looking at your thread to see if there was a solution...
I browsed through a shop manual and figured it out.
Answer: O-RING!
there is an o-ring between your master cylinder and the power boost (black drum thing). When we pulled on the master cylinder, the vacuum that was inside the power booster sucked in the oring. I pulled the master cylinder, and looked inside the power booster. there is a spring looking thing, and somewhere in there should be a black o-ring the size of the opening. Stick your finger in and pull it out!
slide this oring around the outside of the master cylinder, all the way towards the cylinder body. when you put it back and tighten, the o-ring will sit nicely between the master cylinder and the booster, creating a seal. Problem solved. no need to bleed brakes because you didn't actually let any air in.
it's 9pm here, dark out, was working on this all night... tired.
good luck!
Background: I had the same problem. I pulled on master cylinder, there was a hiss, then started having vacuum leak problems, so i was looking at your thread to see if there was a solution...
I browsed through a shop manual and figured it out.
Answer: O-RING!
there is an o-ring between your master cylinder and the power boost (black drum thing). When we pulled on the master cylinder, the vacuum that was inside the power booster sucked in the oring. I pulled the master cylinder, and looked inside the power booster. there is a spring looking thing, and somewhere in there should be a black o-ring the size of the opening. Stick your finger in and pull it out!
slide this oring around the outside of the master cylinder, all the way towards the cylinder body. when you put it back and tighten, the o-ring will sit nicely between the master cylinder and the booster, creating a seal. Problem solved. no need to bleed brakes because you didn't actually let any air in.
it's 9pm here, dark out, was working on this all night... tired.
good luck!
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10-12-2009, 05:45 PM
#8
JK Freak
Thread Starter
Jinkang--thanks so much. I was about to go
pay to have them looked at. Wow that o-ring was sucked way back in there. But I got it and bam!!!! Fixed!!! Thanks.
pay to have them looked at. Wow that o-ring was sucked way back in there. But I got it and bam!!!! Fixed!!! Thanks.
02-28-2015, 04:56 PM
#9
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This thread saved me from a real headache! Coudn't figure out why the booster was acting and sounding funny after adding my compressor bracket. Read the thread, went out and checked, exactly the problem! Easy fix and everything is back to normal, stupid o ring got sucked into the booster.