Hard Brake Peddle/Won't start

[Bananaman]

Bringing up a slightly old thread...
I was also having the stiff brake petal problem. Usually took a week of the Jeep not being driven, but as time went on, it started stiffening up in a day or two. I just replaced the check valve yesterday, so won't know if that will solve the issue yet.
BUT, just to let everybody know; the plastic tube coming off the old valve is molded on (heat shrunk, probably). I rigged mine with a piece of 5/16" hose, but to do it properly, you will need to order that section of hose along with the check valve.

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[Lost1wing]

CDJR are not alone using plastic tubing. At least you know what to look for. Some of the rubber vacuum tubes they use now also gets pretty hard after a few years. DFW and they last a bit longer.

Me son-in-law was trying to replace the air filter on my daughter's Renegade. He took the top of the box off but tried to leave the vacuum lines connected while replacing the filter. He broke the airbox and one tube. He got so pissed at himself that he thought it was best to finish the job by breaking the other tube by throwing a tantrum. $500+ in parts and about an hour to replace it all. He know knows that he needs to disconnect plastic tubes. Even disconnecting can cause premature failure.

 

[ShadowsPapa]

Bringing up a slightly old thread...
I was also having the stiff brake petal problem. Usually took a week of the Jeep not being driven, but as time went on, it started stiffening up in a day or two. I just replaced the check valve yesterday, so won't know if that will solve the issue yet.
BUT, just to let everybody know; the plastic tube coming off the old valve is molded on (heat shrunk, probably). I rigged mine with a piece of 5/16" hose, but to do it properly, you will need to order that section of hose along with the check valve.

Heat gun.
When I put the Jeep 4.0 in my car, I wanted to use as many of the Jeep's hard lines as I could - neater and don't get messy like rubber vacuum hose.
So I used a heat gun - GENTLY - and softened the tube JUST ENOUGH to slip the fitting out of.
I cut and shaped the lines as needed, put the fittings in and heated them to fit.
Some of the connections used a hose over the plastic and over the fitting end, others were direct fitting into plastic line.
I replaced many of the "hoses" in my engine bay with the lines salvaged from a 94 ZJ

Otherwise, not sure if it's been said here before or not - You can usually push hard enough to get the thing started. I think people are used to the lowered force required in modern brakes, where I was so used to manual brakes with no assist, I just instinctively press the pedal harder and get to the point it will start - although it's only happened on my Jeeps once or twice after sitting for a week or more.

 

[Bananaman]

CDJR are not alone using plastic tubing. At least you know what to look for. Some of the rubber vacuum tubes they use now also gets pretty hard after a few years. DFW and they last a bit longer.

Me son-in-law was trying to replace the air filter on my daughter's Renegade. He took the top of the box off but tried to leave the vacuum lines connected while replacing the filter. He broke the airbox and one tube. He got so pissed at himself that he thought it was best to finish the job by breaking the other tube by throwing a tantrum. $500+ in parts and about an hour to replace it all. He know knows that he needs to disconnect plastic tubes. Even disconnecting can cause premature failure.

LOL. I too have caused more repair then the original job called for. In my fathers time honored tradition of throwing a wrench across the garage while I hold the flashlight!

 

[Bananaman]

Heat gun.
When I put the Jeep 4.0 in my car, I wanted to use as many of the Jeep's hard lines as I could - neater and don't get messy like rubber vacuum hose.
So I used a heat gun - GENTLY - and softened the tube JUST ENOUGH to slip the fitting out of.
I cut and shaped the lines as needed, put the fittings in and heated them to fit.
Some of the connections used a hose over the plastic and over the fitting end, others were direct fitting into plastic line.
I replaced many of the "hoses" in my engine bay with the lines salvaged from a 94 ZJ

Otherwise, not sure if it's been said here before or not - You can usually push hard enough to get the thing started. I think people are used to the lowered force required in modern brakes, where I was so used to manual brakes with no assist, I just instinctively press the pedal harder and get to the point it will start - although it's only happened on my Jeeps once or twice after sitting for a week or more.

Yep, I should have tried that first. It just looked so formed on to the nipple that I figured it would never go back on tight.

 

[ShadowsPapa]

Yep, I should have tried that first. It just looked so formed on to the nipple that I figured it would never go back on tight.

Your fix worked - so you achieved your goal.
We aren't looking for concours correct for a car show. (doubt anyone here has a 200 point Gladiator HAHA)

 

[SamJ3]

Does anyone know where to source the just the hard line?

The pre-shaped Mopar part (68358377AB) lists for about $90 (about $60-$75 on many sites). The part (#3) includes the fittings and sensor/check-valve, but all I needed was the hose (#2, but not sold seperately).

Some bulk line and a heat gun would be ideal! (I needed to tap into this line for my towing brake system, and ended up replacing that segment with traditional hoses and clamps.)

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