Brake Fluid

JMT

JMT

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So I'm a little low on brake fluid. Thought I would add some. Manual says Mopar DOT 3. 4 is acceptable. How sensitive are our TJs to Mopar here?
 
I do not think you are supposed to add fluid. Fluid gets low purposely as the brake pads/shoes wear down. Once fluid level gets to a certain point then the brake light appears on the instrumental panel notifying you that brakes need serviced.

It can also get low due to leaking brake lines, fittings, wheel cylinders, etc.

Check your pads and shoes for wear and inspect the rear wheel cylinders inside the drums.
 
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Ahoragi said:
I do not think you are supposed to add fluid. Fluid gets low purposely as the brake pads/shoes wear down. Once fluid level gets to a certain point then the brake light appears on the instrumental panel notifying you that brakes need serviced.

It can also get low due to leaking brake lines, fittings, wheel cylinders, etc.

Check your pads and shoes for wear and inspect the rear wheel cylinders inside the drums.
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I'll get on it. I know my pads are just ok, so maybe BMB pads coming soon to a Jeep near you! But hopefully next year, when I can afford it. The Just Empty Every Pocket saga continues...

The manual does say to add some and that it will get lower as brake pads wear thin
 
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As the disc pads and the brake shoes wear the caliper pistons and wheel cylinders move out in the bores, being low on fluid is as JMT says an indication that things are wearing. Or possibly a leak. But as to the statement you are not suppose to add brake fluid I must respectfully disagree. Check the amount of friction material left on your pads and shoes to be sure, a bit of a no brainer, but do not hesitate to add fluid.

B
 
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Removed a wheel and took this photo. These pads look good, right? The indention on either side shows the pad still has some life, correct?

IMG_6998.JPG
 
You have a long shelf life on the pads, but that is not the problem here.
You need to buy a brake cleaner and clean your brake assembly Sir.
That is after you flush the fluids... I mean flush the fluid, not add.
 
Ahoragi said:
Once fluid level gets to a certain point then the brake light appears on the instrumental panel notifying you that brakes need serviced.
Click to expand...
The brake light on the instrument cluster is there to show when there is uneven brake line pressure between the front & rear brake circuits. If there's a difference in brake line pressure between them, a shuttle valve switch between them inside the master brake cylinder will light the Brake light on the instrument cluster. That typically means one of the two brake circuits is inoperative though sometimes it can just mean the shuttle valve switch is stuck to one side. It's not indicating low brake fluid or brake pad wear like some cars provide indications for.

On the brake fluid issue, any DOT 3/4 is fine, so is DOT 5.1. Just make sure to NEVER use DOT 5 which is incompatible. So DOT 5.1 is ok in addition to DOT 3 or 4 but not DOT 5. :)
 
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Here is a more complete explanation from a March 2012 post by @mrblaine, perhaps the most qualified person to render an expert opinion on TJ brake systems:

From J**pForum.com:

mrblaine said:
The light wasn't on to indicate a low fluid level and that is a very important distinction because you can trip the light with a full reservoir. It only turns on when the shuttle valve is shifted and that only happens when differential pressure is high enough on one side to kick it over.

That tells you there is a problem, from there you need to find out what the problem is. Similar to the CEL, it only means you need to dig into it to diagnose the actual cause.

It can shift from low fluid, a leak in one side, too much travel in a wheel cylinder, sticky proportioning valve, air in the master with the reservoir full, improper bleeding procedures, and other things. Or, the dash light can turn on because you spilled your soda in the console and it glued the momentary switch in place.
Click to expand...

See: https://www.j**pforum.com/forum/f9/emergency-brake-warning-light-1344025/#post13253742] [Replace the ** in jeep with ee]
 
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