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ValourUnbound New Reader
9/17/19 6:14 p.m.

Another option for debugging: is there some way to cap the hard lines? Not just to prevent fluid form leaking but to hold pressure.

I feel like it should be simple enough to cap/plug various location to isolate the issue. For example, cap the rear lines to isolate the drums, front lines to isolate calipers, plug ABS output, etc and test the pedal at each step.  Theoretically it should be simple to find M12-1.00 plugs/caps. I have not found that to be the case. I can barely find screws that size, and those were from China and were only guaranteed to be here before Christmas. I've searched M12-1.00 plugs/caps, brake line plugs/caps and found nothing. Is there a term I'm missing? This seems like a simple diagnostic tool.

kevinatfms GRM+ Memberand Reader
9/18/19 11:08 a.m.

Is the pedal assembly broken at all? Bent?

ValourUnbound New Reader
9/19/19 2:16 a.m.

In reply to kevinatfms :

Nope. Straight as an arrow and it has a clean action and return.

Slight update: I fixed the hissing I heard. Turns out that somewhere between install #1 and install #2 the MC-booster seal disappeared. Luckily the old one was in good shape, so I stuck that in. I made sure I wouldn't lose it in the process too.


AngryCorvair GRM+ Memberand MegaDork
9/19/19 5:56 a.m.

Good work tracking down the booster seal.

You can use vise grips to squeeze off the jounce hose to each corner but don’t crank them down super tight because you will damage them internally or maybe even externally and then you’ll have to replace them.

ValourUnbound New Reader
10/2/19 12:56 p.m.

Alright, after a couple of weeks waiting for parts, I have a new update.

I got a used ABS module from eBay and swapped in the pump only, while keeping my computer.

Before I turned the car on, the pedal felt good. Now, before anyone says that the pedal with the car off doesn't mean anything, I know that. However, I've noticed that I can press the pedal all the way to the floor, while the car is off, without too much effort, even with pumping. This time I couldn't. Then I turned the car on. Same old, same old. To the floor.

On a positive note, I did solve the Mystery of the Missing Vacuum Seals. After removing the MC in order to get the ABS out, I noticed that the seal was gone again. Also that the MC was terribly difficult to remove from the booster. And that it made a loud hiss when I finally removed it. Turns out I forgot to deplete the vacuum before trying to remove the MC, so the vacuum sucked the seals into the booster. Luckily they were both hanging out within reach.

I bled a bit more to make sure I wasn't missing any air, then lowered the car and drove it to work this morning. Really the only issue is that I know something is amiss. If someone else gets in the car, they don't notice anything wrong. The car stops when the pedal is pushed, just like every other car. I'm sure if I drive it for a few months I'll get used to it. What else can I do? If it take it to the dealer I fear they will say that it's air in the brakes, calipers, drums, MC then ABS. Maybe the booster. $3000 later it'll be exactly the same. 

fusion66 New Reader
10/2/19 2:05 p.m.

In reply to ValourUnbound :

This isn't going to help but figured I would at least share what I went through on a similar issue. My first try was a JY unit from Ebay and I only replaced the HCU (pump, manifold, valve system). This did not take care of the issue. My second attempt was with a local JY unit and I replaced the HCU plus the computer that came with it. This solved the issue for me but I have no way of knowing why JY unit 1 did not solve the issue. I did not swap parts back and forth to isolate the issue as it is a painful install process. Good luck - I hope you get it sorted out.

ValourUnbound New Reader
10/3/19 5:05 p.m.

Well... that's something. I suppose I could swap the computer in as well. While I'm at it I might as well replace the MC with the original unit, since that changed nothing, and get my $100 back from Wal-Mart.

There is always the option of going new... but that's a $1000 problem I'm not quite ready for.

It is kind of irritating to replace parts multiple times, but at least I'm getting pretty quick at it. The HCU was really easy once I figured out that the MC has to come out for clearance reasons.

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