2000 XJ dash 'brake' light always on

[hightime81]

Hey All!

checking for my buddie's 2000 XJ, 4.0, 4x4 with 140K on it, AW4.

His dash brake light seems to be stuck on. When he first brought it by i checked the parking brake linkage and all seemed good, until i got to his rear passenger wheel. he has blown the wheel cylinder. I was just going to pinch the brake line, but he was hesitant to do that and would rather replace the cylinder (probably later this week).

That being said, would the blown wheel cylinder be the reason for the dash light being stuck on?

Cheers!

 

[winterbeater]

YES. Brake pressure differential between front and rear actuates a switch.

 

[iwannadie]

My sister has an Xterra, the brake light was 'stuck on' for months before she mentioned it to me. Turned out she had pretty much no brake fluid...

They need to have two different lights I think for the brakes, one for a brake problem and one to indicate the parking brake is on.

 

[RoadHog_ZA]

Dude, that would add 15 cents to the production costs - yah got no chance, mon

 

[kastein]

Yup. And that 15 cents could be saved by lowering pay per union employee by a few dollars per year (not hour, year)... but which is going to happen?

 

[Original_MudButt]

Another possibility is the switch at the parking brake. Not very common, but possible.

 

[hightime81]

Thanks All. i will double check the parking brake, but the light being stuck on due to the leaky wheel cylinder makes sense.

cheers.

 

[LazersGoPEWPEW]

I just noticed that my brake light is now stuck in the on position. What do I need to check?

 

[hightime81]

your brake on the dash? or your brake light itself?

if its the dash light, you have a leak in your brake system

GGGGRAve dig on this thread

 

[LazersGoPEWPEW]

your brake on the dash? or your brake light itself?

if its the dash light, you have a leak in your brake system

GGGGRAve dig on this thread

The parking brake light on my dash is on. Ugh that sucks. I don't even know where to start looking for that.

 

[hightime81]

not that bad really. get under your rear axle and check the brake drums, my bet is you will find one is leaky. unles you have a police model (unlikely) you will have 9" drum brakes, you just need a new wheel cyliner (5$) and 2 feet of 1/4 inch clear tubing so that you can bleed the brakes once you have changed out the wheel cylinder.

my guess is passenger side, don't know why, but that would be the 3rd 01' model that had a failed passenger side wheel cylinder that i know of. my 93's is 17 yrs old and kickin still

let me know what you find! if you dont find a visible leak, you might ust have have some air in your brake system and a bleed cycle is in order.

good luck my friend!~

 

[Shorty]

fill the master cylinder first and pump the heck out of the brakes (sitting still with the engine off) and check for wet spots by each wheel. If the fluid level drops or you find puddles at a wheel, you've got a leak. If the fluid remains full and no wet spots appear, the master cylinder is bypasing either the front or the rear hydraulic circuit and you need a new master cylinder.

 

[hightime81]

are the MC prone to issues on the later models? my main experience is the early HO years personally, but obviously anything could be the culprit.

 

[LazersGoPEWPEW]

If it ends up being the MC should I just buy another stock one or is there an upgrade I can do.

 

[ehall]

The warning light is fed by two switches, one in the parking brake handle, and another in the proportioning block under the master cylinder (this one monitors the fluid hydraulics). Disconnect the connector on the proportioning block to interrupt/eliminate that part of circuit--if the light goes off then the problem is with the hydraulics (difference in line pressure, low fluid, etc), but if the light is still on then the parking brake switch is stuck.

 

[LazersGoPEWPEW]

Well went out and tried what ehall recommended. Light did NOT stay on. So I just sat there and pumped the brakes for a little bit. Then I looked at the drums and no leaks. However I did find a nice leak on the hard brake line going from the front to rear almost right under the drive side seat. The line looks pretty long. Easy replacement?