Hidden brake leak in the cross frame between the engine and the radiator.
01.13.10
Brake Line Repairs
After letting the Prairie Schooner sit for 5 years, I knew there would be problems. The fun part, of course, is finding them.
I found brake fluid pouring out between the engine and the radiator up in the cross frame. No mater what angle I tried to use, I just couldn’t see the exact spot— let alone effect a repair.
Disassembling the front of the engine to get at the cross frame from the top. The radiator had to come out through the bottom! That meant jacking the RV up frighteningly high.
The only solution was taking the radiator out and getting at it from the top through the front. I checked on the internet for a recommended way of getting it out. Advice: don’t do it! Well, that wasn’t an option for me.
The radiator had to come out through the bottom. Nothing is easy— the transmission lines didn’t want to come off, so I had to cut them— and I cut the old hose off the bottom too. What the heck? Good to change the hoses anyway. Right?
Next I had to raise the Schooner up high and drop the radiator out through the bottom. As long as it was out, I dropped it off at a radiator shop for cleaning and repair— it looked pretty dirty.
The brake line still wasn't easy to reach, but it was accessible. Sometime during the life of the brake line, it had gotten bent. Right where the metal was fatigued, it failed.
I was finally able to see the problem: a line with a hole in it. The rest of the ling looked good, but the bad part had gotten bent at some point and that’s where it fatigued. I cut out the bad section and replaced it.
Joining the new piece of line with the existing line requires a double flair compression fitting. A double flair is a double bend on the end of the line that makes for a much stronger ‘lip’. As you might guess, there is a tool for it called a double-flairing tool.
Having gotten that taken care of, I put a paper towel under the line to show me if there are any leaks or wetness, then I bled the lines and mashed the brake pedal. I pushed harder than I ever have while driving— and when I did, something let go.
I matched the bends with the portion of the brake line I removed. The exposed ends needed double flares. I put the new piece in and checked for leakes.
OK. Better here than on the road. I had to crawl around underneath to find the break. The drip was coming from a bend in the line up over the starboard (right) rear shock. I picked a point farther forward and cut the line where it looked like it wouldn’t be too difficult to get the flaring tool up in there.
Bought a long piece of line, matched the bends with a bending tool, then cut the length to match and double flared the end.
Did a good job matching the bends and the new piece fit back in quite nicely. Getting a double flare on the end of the existing piece to 2 attempts to get straight.
Dang! Something popped and I had to crawl around and find it. Well, better to happen now than chugging down a mountain or something!
When I tried to bleed my new line, nothing came out. Right away I knew what that meant: the flex hose had collapsed inside. It’s a common problem. This Chevy P-30 has 5 places where flexible brake hose is used, 3 had already been replaced. Sometimes the collapse will cause a brake to lock up, and sometimes it will cause it not to work.
Well, no sense not to change them both. Problem is, the rear flex lines were hard to find! All the other flex lines for the brakes can be had from placed like AutoZone for around $15. What I discovered was, even though the P-30 is one of the most common truck chassis in the world, for only 2 year disc brakes were used on the back: 1978 & 1979. I tried to have some made, but the hydraulic guys couldn’t get the right banjos.
The back flex hoses were hard to find and very expensive, but I needed them.
NAPA was finally able to run them down for me from a warehouse in IL. Price: $100/pair. Ouch! The front banjos are the same, but the hoses are different, I may have been able to fashion something by changing the ends on a pair of front flex lines, but after all was said and done, I probably would have spent just as much. Plus, getting the ordered hoses gets it done right for sure.
What I decided after going through all this is if I were doing it again, I wouldn’t cut and replace a section of brake line. It worked ok, and it’s safe that way, but the lengths of line are cheap, and laying on my back with brake fluid dripping in my face while using a flaring tool was a bitch. Instead, if I do it again, I will go all the way back to an existing union in the line and rejoin it there. That way, I can match the bends, cut it to length, and flare the ends all on the bench— underneath I won’t need to fool around with a flaring tool in tight quarters. Another plus is that more of the line is new and there is one less double flare to make.
