Replacing hard to reach brake line?

[M & J]

Good news is the new MC is in and that job is complete. Makes plenty of pressure now. So much in fact - the bad news is it blew out a steel brake line. .

Right out of the combination valve, mounted inside the front crossmember inches from the crank pully. Had to be installed before the engine was. I have no idea how I'm going to get it  replaced since i can barely see the line and valve and i dont think i can get a flare wrench in there let alone turn it. Totally disgusted right now....... I cant even see where the line goes. More hoses and frame braces hides it as it runs to the right.

[circleD]

Only advice I can give you man is degrease and pressure wash under there to get a good clear view. Then use a strong hand light to trace it down. Then I'd ask an old school mechanic or "Super Dave" to find any tricks. Then see if it would be easier to just make a new brake line system in that area and mount it differently with new hardware.  i??

[joanfenn]

 .  Mike, just remember, you are smarter than the brake line.

[Schwarzkopf9]

that stinks man! these old rigs get so rusty underneath. i had to soak and torch my lines because the flare nuts were  siezed to them. all came out okay, what a wonder a new master makes! also did the front shocks while i was in there let me tell you, they were SHOT! night and day ride quality. could you just remove the old line up to where the tee is and make a new one? youll obviously need a flare tool and bender. is it the long line running back?

[Froggy1936]

Yes what you have is in a very difficult location . Either you have to remove or mabey just lift (and you will find that the motor mounts are a real Bear.)  Or just get a new valve and replumb more conveniently (best option) Hydrolic pressure does not care about configuration Just make sure you clear all obsticles Frank

[DaveVA78Chieftain]

Now now Mike.  Betty is just saying she has a boo boo  and wanted to make sure it didn't  N:( create a much bigger boo boo  while on the road.

Dave

[Lefty]

As suggested, I'd just disconnect the bad line at both ends, and reroute a new line using a more convenient path. Just make sure that you don't kink the new line when bending it, and that you secure it with line clips where needed so it cannot be damaged by unwanted movement or rubbing.
Just make sure when you route it, that you keep a good distance away from intense heat sources like the exhaust.

[DaveVA78Chieftain]

He is unhappy because the combination valve is in a bad location so to move it is 5 brake lines, not just one.

Dave

[TripleJ]

Did it break the line right at the combo valve?  Do you have clearance to snip the line, flare it and ad in a short piece in place of the broken line?

[M & J]

I have all the tools needed - I've bent and double flared replacement lines for other vehicles.
The problem is access, and the combination valve is no longer available.
While searching for parts I did find a diagram and the line that blew out is the one that runs to the right front caliper. Maybe 3 feet long.

[Rickf1985]

What I usually do with rotted lines is just break it off at the fitting and then use a 5/16 6 point socket to remove the fitting from the valve/cylinder whatever. Installing the new line in your case could be an issue, what about crows foot flare nut wrenches? Like was said, you can route the line differently as Long as it is supported good. The manufacturer does it the way they do to save money on material.

[M & J]

I was able to get back under the coach this evening and removed the blown brake line intact.

Sprayed everything down with penetrant and was able to get a flare wrench on and it and it loosened easily. One hold down clip was rusted and the impact removed it. Other end did route to the right front caliper and it loosened without trouble also.

The hard part was worming the line out since it was behind the rear brake line and steel fuel line plus up and over the frame rail. A little twisting, thinking, some bending and I got it out intact.

There are 4 distinct holes where it looks like it has been ground out. Really odd. The rust is surface and minor. They are all within inches of the combination valve. Maybe gravel got kicked up and vibration wore the holes in the line? I have no idea. Next is about 40 inches of 3/16 steel line, 2 flare connectors and the chinese puzzle in reverse worming the new line back in. The other lines appear to be in good shape where I can see them.

I want to thank Joanfenn for her kind, supporting words, also Brandon and Super Dave for thier good natured goading to not give up.

No pics, my phone pics have trouble sizing to be posted here. More after the next 7 days of rain  passes.

[Rickf1985]

Get yourself one of those small inspection mirrors and a penlight flashlight and check the rest of the lines where you CAN'T see them. That is most likely where they will be rusted. Best to do it now while you have the fluid out of it and you are already sore. I hate to say it but if one is bad the rest are not far behind. I have been a mechanic for 40 years and have seen this a hundred times and even I have replaced just one line only to have another fail shortly afterwards. And I knew exactly what I just told you but I did it anyway. D:oH! I think it is ingrained in human nature.

[M & J]

What do you, or anyone think of using the copper nickel brake line? Forms real easy and so far I've yet to find any real drawbacks using it except where it would be used off road subject to impacts. And it never rusts out.
I got a section of it to use but saved the receipt in case an RV application would not be a good idea. Remember, where this line runs is protected by the front crossmember except where it loops up and over the frame rail.

[Rickf1985]

The biggest problem is that it will work harden and crack if there is any movement near a fitting and also it will wear through quickly if it is rubbing on something. Steel will wear through also but it will take a long time. I bend regular steel lines by hand unless it is a close to the end spot where I cannot get hold of the short end. Then I will put a box wrench on it and very carefully and slowly bend that piece watching for kinks from the wrench. If you are using pre-made lines you can put a 3/8" box wrench on the fitting and carefully bent it from there, just watch that you do not kink it where it goes into the fitting.

[M & J]

I read where stainless steel lines will work harden but nothing about this stuff. I was wondering if it would take the pressure. Or if you had used it.

Anyone else?

[M & J]

I had to pick up a few other things so grabbed a stick of 3/16s steel brake line. A little nervous about using the copper/nickel on a chassis this size.

[Rickf1985]

All brake systems work with pressure averaging around 1200 lbs. on a medium stop. That is the small cars up to the big trucks. What changes is the size of the wheel cylinder which in turn changes the amount of surface area of the piston that 1200 lbs. is pushing on. I have a migraine right now so my math skills are not working but as the surface area of a piston increases the amount of force derived front the same pressure also increases. The master cylinder piston size also increases so it can provide the increased amount of fluid for the larger wheel cylinder but the piston in the master cylinder is always smaller than the wheel cylinders to give a hydraulic advantage. There is also a mechanicl advantage built into all of this in the position of the piston rod for the master cylinder where it mounts to the pedal. The rod mounts closer to the pivot point of the pedal than it is to your foot. Then you have the power of the booster......................... not even going to try to get into that but if you have ever tried to stop without power to it you know what it does.

[M & J]

I spent this morning bending up and flaring the replacement line. I am reusing the 9/16 flare nuts and was able to get the rub spring off the old line and on the new after bending. The tough part was bending the tight radiuses needed. I had a tubing bender for larger radius bends and reversed engineered it to use the rollers for the small ones needed. The double flare went smoothly.
The new line and old are in the pic below. Rain is moving in so it will be a few days before I can install it, bleed and see what else blows out.

[Rickf1985]

I am impressed. I never use the spring cover because it traps salt and moisture and accelerates rust.

[M & J]

If I impressed you then I feel feel really good Rick. Thank you.

The spring goes up and over the frame rail and looked like a good place for the factory to use one. Minimal rust on the old one and it came off easily.

[M & J]

The rain held off so I went to install the replacement brake line. Miserable time doing that.
Worming the new line in was much harder than getting the old line out plus it took me over an hour and several trips walking around to burn off frustration to get the flare nut threaded on the combination valve.
Remember, I can barely see the dang thing and if you've ever messed with flare fittings you know you only get one shot before they crossthread. I couldnt see it and couldnt feel well enough to know if it was aligned before starting the threads. I used a mirror plus ended up unbolting the valve to let it move some. I was able to lift it enough to see so between the mirror (which made movements backwards) I did get it started and it tightened with the wrench without crossthreading.
Both bleeders on the front were froze, 1 came out with vise grips and the other with an easy out. I let the front gravity bleed while I went to get new bleeders then vacuum bled the fronts till the fluid ran clear.
Started up the rig and after a few pumps of the pedal it firmed up and the brake light went out.

Thank Goodness.

Still need to bleed the rear drums and pull new fluid through. I'll rebleed the fronts to be sure and so far, no leaks or any other problems. Then the test drive.

What a job. I hope the brakes work great for another few years, I dont want to have to do this one again.

[Rickf1985]

Congrats on a job well done. Those fittings are no fun and as you say they will strip in a heartbeat. Most people are not like you and instead of walking away for a bit they will rush and force things.
I was looking at some of my lines before my last trip and I think I need to revisit then and go over them real good. The P/O already replaced all of the rubber lines and calipers up front but the metal lines were showing some rust and I don't know about the rears. I do know my emergency brake cable is frozen and I am having a really hard time finding one. Seems GM did not use the drive shaft mounted brake on many things.

[DaveVA78Chieftain]

Rick,
Millsupply (bootom of page) https://www.millsupply.com/stepvan-parts/emergency-brake-parts/emergency-brake-components-19-5/

http://www.dormanproducts.com/p-14410-c93473.aspx?year=1988&make=Chevrolet&model=P30&parttype=Cable%20-%20Parking%20Brake&origin=YMM

Several possibilities listed here: http://www.dormanproducts.com/gsearch.aspx?type=parttype&year=1988&make=Chevrolet&model=P30&parttype=Cable%20-%20Parking%20Brake&origin=YMM

Dave

[Rickf1985]

Thanks Dave, It looks like "G" on that page may be the one. I have the foot operated brake, would rather have the handle brake. I am going to have to get the old one off for measurement and end type to be sure.