Honda CRX Si Brake Woes
- Thread starter darthmonkeyIT
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darthmonkeyIT
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The stock nut on the booster is a real pain. It is actually a 12 pt nut which requires cutting a slot in a 14 mm wrench to be able to get around the nut. This makes the 14 mm box end very weak in relative terms. Further still the 17 mm square behind it is half size so a full 17 mm crescent won’t fit and still allow another wrench.
If you put a flashlight on it as well you may see some yellow torque stripe paint on the nut-square. That paint on mine had seeped into the thread interface and locked them closed pretty good. When we took the booster out, locked it down in a vice, and put a torque wrench on it for kicks it took roughly 100 ft-lbs to break it free. We were never going to get that much force on it inside the car with a chopped open box end.
If you really want to try though from inside the car buy a 14 mm box end and chop a slot in it to fit around the rod and over the nut. For the skinny wrench I bought a 17 mm bicycle cone wrench – 1/8” thick steel wrench. Caution it does hurt applying pressure to that skinny wrench if you really have to push on it.
For us it was ultimately easier to remove the booster and get the nut-square broken free. When you remove the booster you can take off the 14 mm 12 pt nut and replace it with a 17 mm standard hex nut. This makes adjusting in the car a lot easier because now you can use a standard 17 mm open end and the 17 mm cone wrench. It also gets rid of paint and years of grime locking them together.
The pedal slop measurement – make sure the slop you feel has resistance. The pedal will slop a bit prior to engaging the booster rod which is not part of the booster gap measurement. Make sure the slop you are measuring is the booster slop and not the pedal slop.
Thanks. Yeah, I already figured out the wrenches and got the nut loose with the booster installed. What I was looking for was a measurement technique for the booster rod / MC adjustment. Luckily I was able to get a local Honda dealer to loan me the tool so now I don't have to worry about it.
I first set identical lengths for the booster rod and pedal clevis using the old booster for reference, but the new booster output shaft still protruded farther so I have to adjust anyway. The service manual also says to apply vacuum during adjustment. I did not notice it made any difference with or w/o vacuum.
I first set identical lengths for the booster rod and pedal clevis using the old booster for reference, but the new booster output shaft still protruded farther so I have to adjust anyway. The service manual also says to apply vacuum during adjustment. I did not notice it made any difference with or w/o vacuum.
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