Brake failure! (1 Viewer)

[Black LC]

Hey guys
Yesterday i was driving my lc 2001(1hd fte)
And when i apply brake the brake paddle pressed all the way and car did't stop.

But i somehow manage to stop the car.
When it is stopped brake paddle and brake work perfectly.

No alarm or any warning light went off.
But when i parked the car in my garage and pressed brake paddle several times with ignition on a beep and some warning light(abs) come on for like 2 sec.

Now the issue is that i read a thread where they say when these beep and light comes on don't drive the i dont know what to do?

 

[mdcoa]

You almost certainly have a different brake system than the one that's the topic of the "brake failure" thread. I'll bet you have a vacuum booster and regular old brake master cylinder rather than the pump system the US spec LCs have.
Can you post a picture of your brake system and fluid reservoir?
That said, that's a very strange symptom--have you checked fluid levels and looked for leaks at the calipers at all four wheels?

 

[flintknapper]

IF you have pump style brake booster we can help.

 

[JunkCrzr89]

You almost certainly have a different brake system than the one that's the topic of the "brake failure" thread. I'll bet you have a vacuum booster and regular old brake master cylinder rather than the pump system the US spec LCs have.
Can you post a picture of your brake system and fluid reservoir?
That said, that's a very strange symptom--have you checked fluid levels and looked for leaks at the calipers at all four wheels?

I think most HDJ100s with A/T had the same electronic booster as UZJ100s, whereas most HDJ100s with M/T had vacuum boosters.

 

[thibaut]

I had the same problem recently.
I had a new booster pump accumulator done 2 years ago. I hope it was a one off... car has been parked since then but I am using it this weekend. Somewhat unsettling...

 

[Black LC]

You almost certainly have a different brake system than the one that's the topic of the "brake failure" thread. I'll bet you have a vacuum booster and regular old brake master cylinder rather than the pump system the US spec LCs have.
Can you post a picture of your brake system and fluid reservoir?
That said, that's a very strange symptom--have you checked fluid levels and looked for leaks at the calipers at all four wheels?

No leakes and no low oil level.

 

[ben322]

The quick test for this is engine and key off. Pump brake pedal repeatedly until it gets soft. Turn key on on and listen for the accumulator to run. If it doesn't, then you may have a problem. If it's really noisy you may have a problem. This is a really expensive part so get a second opinion if you're not sure.

 

[Black LC]

IF you have pump style brake booster we can help.

The quick test for this is engine and key off. Pump brake pedal repeatedly until it gets soft. Turn key on on and listen for the accumulator to run. If it doesn't, then you may have a problem. If it's really noisy you may have a problem. This is a really expensive part so get a second opinion if you're not sure.

I have tried this. Noise wo no too loud and it turned on after i turn ignition on.

 

[Black LC]

IF you have pump style brake booster we can help.

It got this.

 

[mdcoa]

I have tried this. Noise wo no too loud and it turned on after i turn ignition on.

Another thing to look for is how long does it run after being depressurized. I believe it should only run 30-40 seconds after ignition switch turned to on (don’t start engine, to make it easier to hear the pump).

 

[Black LC]

Another thing to look for is how long does it run after being depressurized. I believe it should only run 30-40 seconds after ignition switch turned to on (don’t start engine, to make it easier to hear the pump).

Yep it only runs about 30-40 sec after depressurized.

 

[flintknapper]

A lot of reading but covers rebuilding the Master Cylinder and ventures into other problems with pump motor, accumulator and related items.

Master Cylinder Rebuild - DIY

Order correct rebuild kit. Part number for 2000 US model w/ ATRAC is 04493-60330 [edit 6/2018 - this part number is correct for all US 100s. Checked with @beno and while online it will only be listed for 2003-2007, its correct for all US 100s.] Kit is around $50, so a bunch cheaper than...

forum.ih8mud.com

 

[thibaut]

I have finally been driving my car for a bit and I have no further issue. When I had the soft pedal goinn to the floor was immediatley after start up. May be there was a glitch in a relay.

 

[2001LC]

Last first: Pumping brake peddle rapidly will set off warning lights and audible alarms, in a proper working ABS brake system. ABS are to only be pressed and held, not pumped.

I've seen more than once, when the brake booster motors commutator has dead spots (worn out spot). Than, at times, the motor will not run on demand, than others it will. If motor does not run, once system pressure drops, we loose pressure and so brake. It is possible the pressure switch or computer is failing. But those typically fail and do not work again (intermittently)

Here a picture of worn out commutator of booster motor.

About 8 out of 10 times. We see corroded brake control wire, associated with worn-out commutator. The wire can be inspected in few ways. First is to peel back the boots at each end of wire and look. If wire is corroded, it's very likely commutator worn out.

This is a good wire. Picture taken with master in place.

 

[Black LC]

Last first: Pumping brake peddle rapidly will set off warning lights and audible alarms, in a proper working ABS brake system. ABS are to only be pressed and held, not pumped.

I've seen more than once, when the brake booster motors commutator has dead spots (worn out spot). Than, at times, the motor will not run on demand, than others it will. If motor does not run, once system pressure drops, we loose pressure and so brake. It is possible the pressure switch or computer is failing. But those typically fail and do not work again (intermittently)

Here a picture of worn out commutator of booster motor.View attachment 2529716

About 8 out of 10 times. We see corroded brake control wire, associated with worn-out commutator. The wire can be inspected in few ways. First is to peel back the boots at each end of wire and look. If wire is corroded, it's very likely commutator worn out.
View attachment 2529717
This is a good wire. Picture taken with master in place.
View attachment 2529718

I will check the wires. But if the wires are not corroded then what could be the reason that this happened? And after this happened i drove the car brake work perfect, pressed hard worked good.

 

[flintknapper]

I will check the wires. But if the wires are not corroded then what could be the reason that this happened? And after this happened i drove the car brake work perfect, pressed hard worked good.

^^^^^
So did mine..... until the next day. Working on mine today, by coincidence. I was shocked to see how corroded the wire connections were at the ABS unit. Not too bad at the motor but at the ABS unit you can't even tell these are screws. Not even sure yet how I am going to get them off.

At motor:

At ABS UNIT:

 

[JunkCrzr89]

^^^^^
So did mine..... until the next day. Working on my today, by coincidence. I was shocked to see how corroded the wire connections were at the ABS unit. Not too bad at the motor but at the ABS unit you can't even tell these are screws. Not even sure yet how I am going to get them off.

At motor:

View attachment 2529987



At ABS UNIT:

View attachment 2529988

That’s ugly! @2001LC has a thread on getting those corroded screws out without damaging anything else.

 

[flintknapper]

That’s ugly! @2001LC has a thread on getting those corroded screws out without damaging anything else.

Guess I'd better try and find that....because I haven't a clue how I'm going to get these off without knackering the posts they are connected to.

 

[flintknapper]

I cleaned up the connection a bit just so I could see what I am dealing with.

No way to use the heads of the screws as they are....so I cut a slot in each one:

A flathead screwdriver is now a good fit, BUT if they don't break loose easily in the morning after soaking in penetrating oil, then I'll probably have to grind the heads off. Looks like there are nuts underneath the posts and I don't want to break the plastic or twist off the post connections.

Got the new Master Cylinder rebuild kit installed without any trouble, but this is going to be a challenge.

 

[e9999]

yes, plenty of good penetrating oil. I'd do it over several days. Not the thing to rush about. Take your time. I've done the slitting bit a few times and had bits of head to shear off.
Obviously you can't use a torch on those, but maybe contact with a soldering iron so it gets almost hot. Should be easy to see when it's too much. Perhaps do that a few times to get it to expand and contract? Could help.

(FK, may want to start your own thread about your adventures?)