Off topic, Anybody ever completely replace brake lines?

lastcowboy32

Well-known Member
Our daughter has a 2000 Jeep Cherokee.

Her brakes are slightly spongy, in that, if you want them to work, you have to either hit the pedal quickly or pump it.

Her pads, calipers, wheel cylinders and such are in good condition and bled.

My feeling is that it's the master cylinder.

She's away with her sisters for a month; so her jeep is in the yard. I figured that, while she was away, I would do the master cylinder. Given the age of the vehicle and the rusty condition of the brake lines, I figured that it would be a good time to just replace them...all of them. My experience is that the lines themselves aren't that expensive, it's just time and routing.

My gut instinct says that I should just be able to drain the system, take out the master cylinder and lines, install new, crack the bleeders on the four wheels...fill the new master cylinder and lines until all of the bleeders bleed...then perform a typical brake pedal pumping bleed procedure on each wheel.

Am I on the right track?
 
Yep, I have blown many a rusted brake line. So, I won't stop you from changing as many as you like. Bench bleed the master cylinder first. Let each line drip, starting from the longest. Make all the connections tight. Changing all should give you peace of mind.
 
(quoted from post at 08:52:50 08/04/15) Yep, I have blown many a rusted brake line. So, I won't stop you from changing as many as you like. Bench bleed the master cylinder first. Let each line drip, starting from the longest. Make all the connections tight. Changing all should give you peace of mind.

After bench bleeding the master, would it make sense to try to plug all of the ports...then connect one line at a time to "drip bleed" as you recommend?
 
Check with CLASSIC TUBE, their whole business is making replacement brake & fuel lines. They have a great
website! They offer complete stainless steel lines for a small additional charge. I had to wait a week or
so for them to ship the kit for my '96 F-250 4wd, includes EVERY brake line on the whole vehicle.

The flexible rubber covered hoses getting soft or spongy is probably the cause of the spongy brake pedal.
May as well do all the lines, metal & rubber covered.
 
(quoted from post at 09:42:03 08/04/15) Check with CLASSIC TUBE, their whole business is making replacement brake & fuel lines. They have a great
website! They offer complete stainless steel lines for a small additional charge. I had to wait a week or
so for them to ship the kit for my '96 F-250 4wd, includes EVERY brake line on the whole vehicle.

The flexible rubber covered hoses getting soft or spongy is probably the cause of the spongy brake pedal.
May as well do all the lines, metal & rubber covered.

Agreed, if I do this, I'm going end to end master cylinder to wheel cylinder/caliper. It's an old vehicle, but it runs, she has good tires on it. It goes anywhere. I just want to make sure it can stop as well as it goes.
 
Like they said - bench bleed. I hate replacing
master cylinders. It seems as though you can get
the air out of any one part of the system but once
you take the master away air just hides everywhere!

I did do one of my old cars when I did a frame off
restoration. It was so easy to do then. I would guess
it won't be bad as long as you resign yourself to
having a union or two where there used to be one
line. If your try to make those long ones work you
will end up kinking something. Just use a union
block and two smaller lines.
 
Replacing some of the lines you probably need a line wrench crows foot on an 18 inch extension to get at the fitting above the rear . Are you considering there is also anti- lock lines too. It is a heck of a job replacing lines . The saying "If it ain't broke "comes to mind.
 
I understand, but it's laid up for a month right now. Seems like an opportune time to do this. What little brake work I have done on this vehicle has already been complicated by rusted fittings, rusty lines, etc.

A surprise failure in winter with my twenty-one year old daughter at the wheel is a circumstance that I would rather avoid.

To me, it seems like a cheap insurance policy.

If there are fittings and such that aren't easily accessed, to me, replacing the lines also is a cure for that. Once the old lines are out of the picture, I can just cut those fittings out of the picture and re-route new in a better location...or destructively remove the uncooperative fittings to reuse their routing locations.
 
Some later vehicles with 4 wheel ABS require a specific brake bleed procedure. You may want to investigate further if it has 4WABS.
 
(quoted from post at 12:08:32 08/05/15) Some later vehicles with 4 wheel ABS require a specific brake bleed procedure. You may want to investigate further if it has 4WABS.

That is my biggest fear, even with doing just the master cylinder. It isn't just a master and four brake lines anymore. There is a bunch of other stuff involved.
 
If you replace all the metal brake lines why not replace the rubber ones too?
Any more on these vehicles of today I pay to have work done on mine. If were my daughter's vehicle and I did the work and if something would
happen because of some work I done on it and wasn't knowledgeable in a certain area I could never forgive my self.

Remember one thing when working on automobiles.."Brakes Are The Most Important System On All Vehicles" !!
 
my 1969 marquis convertible is having that done rite now ,, rear brake issues ,, that hang and uneven braking,,. not a good thing ,,. I have seen a lot of nasty fluid come thru the bleedrs , the wheel cylinders will straighten up after new fdluid gets in there hopefully ,.. I still have btw the original calipers and frfont discs on this car ,,.never lets the pads weardown to steel ,before changing the pads ,, I have owned this mercury since 1974 , when it had 68 ,000 miles ,, I watchedthe odometer go over 100000 three times,.,.
 
You are the one there looking at so I can't say for
sure but usually on a jeep especially if I do one line
the rest are soon to come. I'd change them all. The
bleeding process is the same as a conventional
pump up and hold methods. I've never been able to
gravity bleed anything with abs.
 
I own 2 cherokees, 93, & 90, have had 1 before too 92, and have rebuilt the brake systems on all of them, i use them for work.
There is no need to replace a line unless there's a leak. One way to tell if it's the master cylinder is if you go over wash
boards and then loose your peddle. Otherwise, my bet, is you still have some air still in the system, or a loose connection, and
replacing parts is a waste of money. Go back and bleed it again, start with the one farthest away from the master cylinder, and
work your way around.... I've had to do this process 4 times before i finally got it all.
 
(quoted from post at 06:46:28 08/07/15) I own 2 cherokees, 93, & 90, have had 1 before too 92, and have rebuilt the brake systems on all of them, i use them for work.
There is no need to replace a line unless there's a leak. One way to tell if it's the master cylinder is if you go over wash
boards and then loose your peddle. Otherwise, my bet, is you still have some air still in the system, or a loose connection, and
replacing parts is a waste of money. Go back and bleed it again, start with the one farthest away from the master cylinder, and
work your way around.... I've had to do this process 4 times before i finally got it all.

That's interesting about vibration from driving over a washboard making the pedal go spongy. I haven't driven it enough to put the two events together. I just know that sometimes it's good. Othertimes it's not.
 
Oh yeah, I got a real education with my '90, it was the first year they came out with ABS, it was recalled, the master cylinder
and proportioning valve was 1500$, used, back east. When i first got it the ABS light was on, and it would work ok until i hit
washboards, then the peddle would go to the floor, and i'd have to pump it to get it back. So whoever owned it before me, went
back to the other way (all ABS stuff was removed), well, i never have been able to get the brakes to work like regular, even
though i went completely through the system, twice, calipers, cylinders, lines. I ended up inserting a small ball bearing (7/16)
in the master cylinder before bolting it up, The first one i put in was too big, and i burnt my new pads, so i put a smaller one
(1/4) in, it works much better, but still not normal. I also had a leak in the back line, and numerous other adventures, i think i
could write a small book. :) I don't know much about ABS, so i go back to, bleed, bleed, and bleed again... it's a pain, but it
will work i think.
 
(quoted from post at 17:07:01 08/08/15) You may need a new master cylinder. Bench bleed the new cylinder before installing. Hal

Hi Hal, Chris here.

I suspected the master cylinder and still do. My thought about replacing lines was that it would be an opportune time to replace them when I replaced the master cylinder...I figured...I'd have the whole system opened up anyway...part of the issue could be water in the fluid...why not just shotgun the whole friggin mess?

Now, one of the replies above has me a little scared and wondering. 1500 for a new master cylinder and proportioning valve?

When I looked into parts, I can get a master cylinder for 50bucks. I can get all of the metal lines for about 200. I haven't priced the short rubber lines yet...but I wouldn't be anywhere near 1500. Is that 1500 including labor at a brake place?

I was hoping to get the whole thing (new master, new lines etc) done for under 300-400 bucks plus my labor. Am I dreaming?
 
I have changed all the steel lines on two different
vehicles. I bought the tubing and a double flare
tool. One job that was definitely not fun.
I wouldn't even try to get them from the dealer.
 

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