Hard brake pedal after I did heatercore.

gbennett21

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Hey guys im going to try and explain best I can.I did a Heater core job on son 2003 Liberty.Which im still not able to all the air out. But the problem started when After that I used the parking brake while I was working on it. And had to move the shifter to 4 lo to get center console out. Everything on this jeep seems to never been used anyway got stuck in for low manage to manual shift back to 2Hi. But brake pedal is Super hard now. They start off normal then as we drive they progressive get hard to press. I can let car sit for a while and its back to normal. but after alttile driving it gets hard and seems to me rear brake gets locked up. Took everything apart and removed parking brake. Also check valve and break boost seems to work fine with the foot pedal test. I tested vacuum from manifold its around 18hg. I can smell rear brakes heating up and when pedal gets hard to press the jeep dont want to move like almost 4000 RPM to get to 30mph. Ive tried eveything I can think of. Reinstalled the same pads and rotors and greased everything. It was **** dry. Also like I said if I let it sit awhile eveything works fine until you drive awhile.This was not a issuk before heatercore job. When I had to move the Shifter to 4lo and the e brake. Also I tested the 2Hi and it is in 2Hi.
 

LibertyTC

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Welcome, Ya sounds like your parking brake shoes are sticking, too tight, & needs adjustment by rear spinners.
The in hat design of the rear parking brake can Be a PITA. Normally use a new spring kit/ shoes and make adjustments properly.
The parking brake shoes can be often very worn down.
2003 Jeep, Is it an ABS? Here is the factory manual for you. http://www.colorado4wheel.com/manuals/Jeep/KJ/2003JeepKJServiceManual.pdf
 

gbennett21

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I already took the hats off and the pads fell apart so I just left the backing of the pads on there and adjusted the star all the down so they dont rub. I know they say there self adjusting. so Im woundering if they spread back out on there own again. I didnt put new parking brake pads on because around here you never use it.
 

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Do you have rear drums or rear disc's? I know the 2002's have drums, but I cant remember if the 2003 was a switch over year or what...

If you have disc's, the parking brakes are NOT self adjusting. When you pump up the brake pedal and it gets hard and stays hard while driving, loosen a rear bleed ***** and see if it goes back to normal. If it doesnt, you may have a bad brake hose. Either the hose going to the rear caliper, or the hose going to the rear axle.
 
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gbennett21

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It has disc brakes with the e brake inside of the hat. Today I drove it around fine praked in driveway on incline let run awhile jumped back in and after two or three stops brake pedal got hard and jeep was hard to get back home rpms were high and when I let off gas it slows down real fast got in drive way and I have that smell again. I havent notice this smell tell this happens. I can olny pump pedal with car off made two times because its kind of hard already you wont get it to the floor. when I do the brake boost test(pump brakes tell hard then turn car on it goes down some) The brake pedal is easier to push when car is on. Driving my other vehicles they are alot softer then this jeep when the car is off. Its like the brake pedal is hard already but I can pump it about two to three inches before it gets rock hard with the vehicle off.Do the parking brake expand back out on there own. or do I have to use the parking brake lever to get them to open against the roto. I only ask beacuse the pads fell apart off the backing and I just ran the adjuster all the way down to back them off. so they wouldnt rub the inside of the rotor.
 

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is it possible that the park brake cable at the handle end is sticking and not allowing the drum to release?

Like even if the handle is released, but the cable does not ‘go home’ to release the shoes from the drum.

It the friction material came unbonded, the shoe could still expand against the drum. Would result in drag on the rear wheel, and grinding sound.
Pretty evident if this is happenin- the shoe itself would show signs of grinding.

Can you tell if it is both sides involved?
 

gbennett21

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im thinking just taking whats left of the e brake pads out and pulling parking brake cable off.we dont use it here in kansas thats part of the problem everything is rusted up because no one used it. my question is if its the parking brake then how is it after some time sitting in drive way brakes work fine then its like after driving around acts like back brakes are dragging or stuck. ( jeep slows down brake pedal gets hard as rock but wont stop car. and I notice if im at a stop sighn with it in drive it wont roll foward any.you no what im trying to say there like when you let your foot off brake pedal at stop sighns the car should roll some. when pedal gets hard it wont roll unless you give it alot of gas like 4000rpms just to go 30mph let off the gas and its slows down fast like your slowing down with brake.
 

gbennett21

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If anyone done a heater core knows there is a vacume line that comes off the break booster to run your blend doors goes in under hood by the ac lines into fire wall if that line is pinched or anything would that cause these problems. after I did heater core that line could of got pinch some but all heating and ac doors work and there is vacuum going threw there. Om asking beacuse I didnt have any problems before taking dash out to put heater core in. but That also was the first time we had to put it in 4lo and use ebrake to get center console out.It was so rusted up.
 

JeepJeepster

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The parking brake will not expand back out unless you pull the handle. If the material is gone from the park shoes, it would be making a terrible sound if the parking brake was being used. Its normal for the brake pedal to get hard when the engine is not running. I cant imagine this issue has anything to do with the brake booster vacuum hose.

Coincidences do happen.
 

DadOSix

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There is a procedure in the service manual, around 5-44 that talks about locking out the park brake cable tension. Might be worth a try.

As to why it is ok, then acts out, i dunno. Only other thing i have is a bad hose. Lumen (inside) opens on pedal, but may collapse when pedal released causing the caliper to stay engaged. This is why i was curious to know if you see evidence on the shoes from dragging on either or both sides.
 

gbennett21

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I will check pads of that im thinking along the same lines . either a hose or caliper.Just odd it happen as soon as I was done with heater core. which is still not getting very hot itself its like fluid is not getting in there this thing is the hardest thing ever to burp system
 

DadOSix

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Did you get the bleeder loose on the water outlet? My 04 won’t budge. The 06 burps easily thru there.
 

duderz7

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I'd take a real close look at your rubber brake lines, especially the center one (you haven't mentioned it pulling) down to the axle. Rubber lines can swell shut with age at which point they no longer release. Often an external inspection for bulging and cracks will tell you. And if one is bad the rest are not far behind.
 

JeepJeepster

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Post #4 will tell you how to figure out if you have a bad brake hose...

And Ive always had to use a little heat to get the coolant bleed ***** out on a 3.7/4.7. The 3.7 in the liberty with the closed cooling system doesn't really need to the bleed ***** removed though. It self bleeds through the small hose that runs from the radiator to the coolant reservoir.
 

turblediesel

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Next time it does it stop and check the calipers and rotors with your hand to see how hot they are.

Years ago I had a master cylinder go bad like that but the car stayed stopped until pressure was bled at the calipers. Maybe a siezed caliper?
 

Parkroad22

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Hey guys im going to try and explain best I can.I did a Heater core job on son 2003 Liberty.Which im still not able to all the air out. But the problem started when After that I used the parking brake while I was working on it. And had to move the shifter to 4 lo to get center console out. Everything on this jeep seems to never been used anyway got stuck in for low manage to manual shift back to 2Hi. But brake pedal is Super hard now. They start off normal then as we drive they progressive get hard to press. I can let car sit for a while and its back to normal. but after alttile driving it gets hard and seems to me rear brake gets locked up. Took everything apart and removed parking brake. Also check valve and break boost seems to work fine with the foot pedal test. I tested vacuum from manifold its around 18hg. I can smell rear brakes heating up and when pedal gets hard to press the jeep dont want to move like almost 4000 RPM to get to 30mph. Ive tried eveything I can think of. Reinstalled the same pads and rotors and greased everything. It was **** dry. Also like I said if I let it sit awhile eveything works fine until you drive awhile.This was not a issuk before heatercore job. When I had to move the Shifter to 4lo and the e brake. Also I tested the 2Hi and it is in 2Hi.
Proofread before posting.
 

Michael Wolfe

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Brake issue sounds like the brakes are dragging and heating up the fluid until it boils. Check that the service brake pistons move properly, you shouldn't need a c clamp to push the pistons back into the caliper. check to make sure the sliders for the caliper aren't stiff. The caliper should move side to side to allow for wear of the rotors and pads. I've also run into issues with the hoses not allowing the fluid to return to the master cylinder. At 190k, I've had to replace all of my calipers and hoses on my '05.
 
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