Losing Brake Fluid - Pirate4x4.Com : 4x4 and Off-Road Forum

highsidezx12r · 01-31-2011, 12:00 PM

I've bought a used 2003 TJ and seem to be losing about a 4oz of brake fluid a week. However, I do not see any signs of it leaking, but it's really hard to tell since my garage floor and jeep are both a mess from the winter weather. Are there certain things that the TJ is prone to leaks that I should check first? I have a soft parking brake too, it barely holds, could this be a related problem.

LeadfootCJ7 · 01-31-2011, 12:07 PM

I would look into the rear brakes then. They could be coated with the leaking fluid keeping the parking brake from being able to hold.

Ho Shorts · 01-31-2011, 12:23 PM

This is a longshot, but I have seen this before on a Jeep. IF you search all 4 wheels, brake lines, etc. and still can't find any leaks pull your master cylinder. I have seen one that the rear seal was bad and it would expel fluid into the brake booster which would in turn get sucked into the intake on the engine and get burnt up and dissappear. This was HELL to diagnose and took a while for me to figure out. All you have to do is pull it and you will find traces of fluid inside the booster if it is happening.

It's much more likely just a leaking caliper or something though.

mrblaine · 02-01-2011, 05:45 AM

Quote:

Originally Posted by Ho Shorts

This is a longshot, but I have seen this before on a Jeep. IF you search all 4 wheels, brake lines, etc. and still can't find any leaks pull your master cylinder. I have seen one that the rear seal was bad and it would expel fluid into the brake booster which would in turn get sucked into the intake on the engine and get burnt up and dissappear. This was HELL to diagnose and took a while for me to figure out. All you have to do is pull it and you will find traces of fluid inside the booster if it is happening.

It's much more likely just a leaking caliper or something though.

Have you ever seen a leaking caliper on a TJ? I've seen brake lines, wheel cylinders, seals in masters, bent banjo bolts, and damaged braided and rubber flex hoses leak, but never a caliper.

Also if the master is leaking back into the booster, you get to replace both of them. Brake fluid ruins the diaphragms.

mrblaine · 02-01-2011, 05:47 AM

Quote:

Originally Posted by LeadfootCJ7

I would look into the rear brakes then. They could be coated with the leaking fluid keeping the parking brake from being able to hold.

It seems counterintuitive but typically rear brake shoe contamination by gear oil or brake fluid makes them lock up harder. Not sure why, but it just works that way.

highsidezx12r · 02-01-2011, 09:31 AM

Thanks for the suggestions guys. When it gets above 0 here or the wind stops blowing then I think I'll start tearing down the rear first and work my way to the front.

djelliott916 · 02-01-2011, 09:42 AM

Quote:

Originally Posted by Ho Shorts

This is a longshot, but I have seen this before on a Jeep. IF you search all 4 wheels, brake lines, etc. and still can't find any leaks pull your master cylinder. I have seen one that the rear seal was bad and it would expel fluid into the brake booster which would in turn get sucked into the intake on the engine and get burnt up and dissappear. This was HELL to diagnose and took a while for me to figure out. All you have to do is pull it and you will find traces of fluid inside the booster if it is happening.

It's much more likely just a leaking caliper or something though.

X2

And sometimes when you hit the brakes, you get a little puff of white smoke out the tailpipe.

highsidezx12r · 02-22-2011, 01:33 PM

It finally dried up around here last week, and it was dead obvious then where the leak was from. The right rear wheel cylinder was bad and leaking like crazy. It's all good now though. Thanks for the info on the master cylinder, I will keep it in mind if I notice any other problems later on.

01-31-2011, 12:00 PM	#1 (permalink)
highsidezx12r Registered User Join Date: Mar 2010 Member # 155322 Posts: 17	Losing Brake Fluid I've bought a used 2003 TJ and seem to be losing about a 4oz of brake fluid a week. However, I do not see any signs of it leaking, but it's really hard to tell since my garage floor and jeep are both a mess from the winter weather. Are there certain things that the TJ is prone to leaks that I should check first? I have a soft parking brake too, it barely holds, could this be a related problem.

01-31-2011, 12:07 PM	#2 (permalink)
LeadfootCJ7 Granite Guru Join Date: Jan 2007 Member # 85264 Location: Houston, Tx Posts: 926	I would look into the rear brakes then. They could be coated with the leaking fluid keeping the parking brake from being able to hold. __________________ 81 CJ7 258/NV4500/Dana 300 4" Skyjacker lift & 1" BL; 4.10 gears, Detroit lockers, Warn M8000

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

01-31-2011, 12:23 PM	#3 (permalink)
Ho Shorts Rock God Join Date: Feb 2008 Member # 109328 Location: Maryville, TN Posts: 1,563	This is a longshot, but I have seen this before on a Jeep. IF you search all 4 wheels, brake lines, etc. and still can't find any leaks pull your master cylinder. I have seen one that the rear seal was bad and it would expel fluid into the brake booster which would in turn get sucked into the intake on the engine and get burnt up and dissappear. This was HELL to diagnose and took a while for me to figure out. All you have to do is pull it and you will find traces of fluid inside the booster if it is happening. It's much more likely just a leaking caliper or something though.

02-01-2011, 09:31 AM	#6 (permalink)
highsidezx12r Registered User Join Date: Mar 2010 Member # 155322 Posts: 17	Thanks for the suggestions guys. When it gets above 0 here or the wind stops blowing then I think I'll start tearing down the rear first and work my way to the front.

02-22-2011, 01:33 PM	#8 (permalink)
highsidezx12r Registered User Join Date: Mar 2010 Member # 155322 Posts: 17	It finally dried up around here last week, and it was dead obvious then where the leak was from. The right rear wheel cylinder was bad and leaking like crazy. It's all good now though. Thanks for the info on the master cylinder, I will keep it in mind if I notice any other problems later on.