tvarghese

Greetings All!

I have a question about my 2005 Acura RL I have had for about 10 years+ and now my daughter has been driving it for the past couple of years.

With the car off pumping the brakes does make it really hard. But if I hold the brake pedal and start the car the pedal sinks down pretty far. Under normal conditions the brake doesn't really seem to engage noticeably till about half way through the range and really engage until about 3/4 of the way. But it is consistent. Is this normal? Or perhaps a bad Master Cylinder?

She had said that the brakes were acting funny and brought it home a couple of weeks ago. I looked at it and the rear caliper had frozen up. The front caliper cylinder boots were ripped on at least one of the four cylinders on both sides. So I got calipers for not too much money off ebay and they were all in pretty good shape, installed them and all went well. The pads were not the best and had damaged the rotors, so I replaced all of those too with Akenobo pads and Bosch rotors.

I bled the brake lines afterwards, using DOT5.1 that I found on sale. I have one of those Phoenix reverse bleeder things and tried it for the first time and it seemed to work pretty well. I tried the gravity bleed and the old style two person pumping the brakes too. Nothing seemed to make much difference at all. Brake pedal is still squishy.

She had gotten to used to the lousy performance so thought this was a great improvement. But it still does not seem right to me.

Is it worth getting an OEM Master Cylinder for around $300 or can is it ok to get one from AutoZone for $75? This is a safety issue, so it seems like an OEM MC is warranted.

I had replaced it once at about 100K miles and now the vehicle has about 185K miles.

Thoughts?

MjAuto

My brake pedal in the RL (110k miles) is definitely not as quick grabbing as my other (newer) cars, but it does grip well 1/2 to 2/3 down like you mention. It could be the master cylinder, though if the brakes were okay prior to the caliber failure, I would initially guess that you may still have a little air in brake lines since the fluid is all new and the pedal goes all the way down. But since you went through 2 different ways of bleeding the brakes and have the same results, either live with it the way it is or go through with the MC change. Maybe your new pads need some time to settle in... after I change my brakes, I usually take the car out and do a few 35mph hard stops (with no one behind me) to help set the pads.

Brakes are important, so if it were me and I was going to replace the MC and keep the car for a while, I'd get an OEM MC, but depends on your budget and how long you plan to keep the car.

tvarghese

Thanks for your response. The Akenobo pads explicitly say that there is no break-in required.

Since it could take a while to get the MC from Acura/Honda, I was thinking I would get one from Autozone/OReillys/etc. for now and get the OEM on order too. Sure I have to do the work twice, but at least the car is likely safe to drive for a short period of time.

Blues Legend

IIRC, the RL has a 1" master cylinder, compared to 1 1/4" in my other Hondas. So there is a lot of squishy travel and not the firmness compared to the sportier models.

Previous experience of caliper swaps suggests that Honda brakes are absolute swines to bleed, so I'd suggest that's more likely than the master cylinder. Might as well try a re-seal kit if you can find one, though - it's an old car. Then again, tired hoses can also sometimes be a cause.

Once the air is in the ABS module (especially with a reverse-bleed) it's a PIA to shift it. Some swear by gravity bleeding, some by a vacuum pump on each caliper, others by a top-pressure bleed.

Sometimes activating the ABS prior to bleeding seems to help. Italian brake tune-up...

I think that cars with a rear load-apportioning valve are the worst - you can only get a dribble from the rear bleed nipples and not a squirt.

tvarghese

Thanks for the responses! Somebody else also suggested it could be the ABS system and decided to investigate that instead of doing the MC, which is a bit of a PITA.

I did a bleed on the ABS unit using a relatively inexpensive scan unit from CGSULIT, the SC530. I had done this before, but I barely had my foot on the brake and I did it just once. This time I had my foot firmly on the pedal and I did it three times. Now the pedal is a lot stiffer than it used to be. It starts noticeably braking about an 10-15% down and hard braking about 25-30% down. I didn't do a bleed at the calipers since it is pretty firm now. Should I?

Thanks all!

tvarghese

Also, the Honda/Acura MC is on back order. The one from OReilly's seems a bit flimsy to me, I will try to return it.

Blues Legend

Maybe give the calipers a bleed in a few days - just in case some residual air has got in there.

It's meant to travel upwards to the MC though, so it's unlikely if they were clear and the ABS body was the problem. As usual...

Handy scanner, that!

tvarghese

Unfortunately I had to take back to my daughter 330 miles away. She may come back down in a couple of months. If she does, I'll try bleeding it again. But I do feel better that the pedal is not squishy and all the calipers are in good shape.

As for the scanner, Amazon accidentally sent me the SC530 instead of the SC630 I ordered, so I reordered and had both on hand. I tried the SC630, it didn't work. tried the SC530 and by some stroke of pure luck it was one that was configured for the Honda/Acura. From what I read they are configured for a specific subset of vehicles and need to be purchased for a specific brand. Not sure how this happened. The SC630 is supposed to work on a wider variety of vehicles, so I'm going to try one more time.