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StansCustoms · 04-28-2015, 07:50 PM

This is Beckey. Stan drove our '01 Alpine out to a big swap meet at Texas Motor Speedway. ABS light came on and he found the RR ABS sensor off and melted, so he knows what the light was for BUT the right front brake is semi-locked up and the pedal is very soft and fading fast.

Question 1-where is the master cylinder located on this year model.

Question 2-Any ideas as to what the problem could be?

Any help would be appreciated. He won't be able to drive it home in the condition the brakes are in right now.

Old Scout · 04-28-2015, 08:27 PM

MC is the fender well, in front of the driver's side front wheel, directly under the floor below driver's seat. You can see the end of the MC in the drivers side, front wheel well. Melted sensor sounds like pads are locking up/dragging. When was brake fluid flushed/replaced? Build-up of mositure over time in brake fluid will cause rubber seals/gaskets to swell and allow pistons to stick.....heat build-up will cause pedal fade...believe 2001 has 4-piston calipers so brake flush requires wheels off bleeding.

StansCustoms · 04-28-2015, 08:53 PM

Thank you for the information. He remembers seeing the MC now that you jogged his memory. He's been a mechanic for a lot of years, just not on Alpines. He is very knowledgeable on mechanical things, so If it sounds like he has no idea what he's doing, it's just the way I am relaying his messages. How often should the brake fluid be flushed/changed?? And you said the wheels have to be off to bleed them-Am I understanding that correctly?

Again-thank you for the help.

Beckey (wife)

StansCustoms · 04-28-2015, 09:32 PM

Stan finally found the manual on the brakes (we knew we had it, just couldn't locate it). It says that if a sensor goes bad, the brake on that wheel goes to manual mode. If he unplugged all 4, would they all go to manual brake mode so he could cripple it in?

Old Scout · 04-29-2015, 12:32 AM

Sensors are a symptom--not the cause.....again, sounds like pistons are sticking and pads are dragging.....change fluid every 3 years ....2 if a really wet climate.....need to verify that 2001 has 4-piston calipers....if so, must take wheels off [rear ones for sure] to bleed all 8 bleed screws.....

twinboat · 04-29-2015, 04:08 AM

If the brakes feel hung up, your going to need repairs, not bleeding. The damage is done.

Make sure the brake pedal is not sticking down a bit, causing the brakes to drag.

The flexible brake hoses, can break down, inside, causing the pressure to not realise.

The calipers can be seized from corrosion.

If you continue to drive it, you could loose all brakes.

Find a cause for your problem, fix it, then worry about changing the fluid.

dennismhamm · 04-29-2015, 06:52 AM

Old Scout, do the wheels have to come off on the 2006 models?

StansCustoms · 04-29-2015, 06:53 AM

Thanks again everybody. We depend on this forum and the wealth of knowledge available through it. We'll try to find the problem and go from there. If anything else comes to mind, I'll be checking back in periodically.

Old Scout · 04-29-2015, 07:00 AM

OK, it was late, I was watching the Spurs, but I wasnt advocating that simply bleeding the system would solve the problem. Think I made it pretty clear that the sensors were a symptom and the real problem was with the pads dragging. Good point on the brake pedal being hung, I have seen atleast one thread where a "bundle of wire" under the dash had shifted and caused the pedal not to release all the way.
The OP also asked about bleeding, accordingly I wanted to make sure they knew about the wheels off procedure. As for periodic flush and fluid change, I am not sure what the "recommended" period is. I do know that I let my 03 go far too long before doing my first wheels-off bleed--but I was luck. Now thinking every3-4 years is about right. Not sure whether climate, frequency of use, or style of braking, has any impact on the need to change fluid. As always, opinion are welcome here.

Old Scout · 04-29-2015, 07:06 AM

Dennis--short anwser is yes....Only the first couple of model years came with a different style of brake caliper. Since 01 or 02, Aplines have all come with 4-piston calipers.....you might get at the front wheel outside bleed screws but the rear wheels are impossible.....IMHO

StansCustoms · 04-29-2015, 10:05 AM

It's daylight and Stan can see now. Said he feels like a fool-he looks at the MC every time he opens the generator. He was tired and wasn't thinking straight. The MC is almost completely full, so that is not the issue. He's going to try to get the front wheel off today to see what the problem might be with the caliper on that wheel. He hadn't thought of the brake pedal sticking, the coach drove normally for the first 15-20 miles. He has also determined that we have 2 coach batteries that have gone bad during winter storage. Do those have any effect on the brake system and can they be replaced with gel batteries?

gatorv · 04-29-2015, 02:30 PM

Stan

You can see the front rotors in the holes through the wheels. If they are badly cracked? Your brakes are trash as mine were. I got the part numbers right off the calipers and the local Napa store had everything ( calipers,pads and rotors)the next day. I was able to make it home but I had the parts with me in case I couldn't. If your going to DYI? Make sure you have lots of help and powerful air tools. Doing my exhaust manifold now, Another back breaker. Good luck.

Dave Fernandez · 04-29-2015, 03:02 PM

Sounds like a piston on the caliper is sticking and not retracking completely causing it to drag. If the rotors are good you will only need to replace the calipers. Replace both front at the same time along with the brake pads. Inspect the rear rotors and calipers replace if necessary. Do a complete brake fluid flush and you should have no more problems for years. And remember to flush the brake fluid every couple of years.

The 2001 model year was the first year for the fixed 4 piston calipers. There are a couple of 2001 Alpines with floating 2 piston calipers which was a hold over from the previous year model. The floating calipers need the pin sliders lubed regularly lubed along with flushing the break fluid.

StansCustoms · 04-29-2015, 03:56 PM

Thanks again everybody. Maybe he can get a little bit of a look at the front rotor through the holes in the wheel like you suggested. You may be right about the caliper sticking and not retracting all the way. That could account for it driving normally and then suddenly developing the problem. We have a lot of things to look at now-we didn't really know where to start. Stan hasn't had much luck getting the front wheel off yet. You'd think at swap meet you could find just about anything to fix anything, but not yet.

Please keep the information coming-we need all the ideas we can get.

Thanks again-Beckey