It was a long road to get here, but when you have a caliper hose that just won't come free from the hard line, a reasonable person asks himself "isn't it ultimately better to just break out the cutting wheel & replace 36 year old steel lines with brand new stainless steel?" The net result will be 100% brand new brake everything short of the pedals & linkage. This will attempt to document that project. You can read all about how I got to this point here (regarding drums & parking brakes)
and here (regarding disc brakes & trouble with unscrewing the hoses)
. I've had trouble, but mostly because I'm a n00b......but I'm getting better.
I went with Classic Tube stainless steel for a 79 CJ7 with manual disc/drum, Morris p/n 531005
for $154 (less $10 & free s/h, thanks Morris 4x4!). I heard good things about Inline Tube, but cheaper price + coupon + free shipping = go with Classic. They arrived on Friday, and look outstanding. I'm a little confused at one or two of the bends on the m/c line, but I'll ask a formal question on that later. Some of this will be chronological, some will be me pretending to have done it in a smarter sequence.
I'm also going to attempt to do it by removing as little as possible. This will either serve as a guide, or a warning to future readers.
1) Isolate the master cylinder
In order to minimize how much fluid I dripped on the floor (and therefore lose from the m/c) I disconnected the lines from the m/c (that's a 1/2" on the forward port & 9/16" on the rear port) and installed the fittings & hose from my bench bleed kit. I had just replaced my m/c, so these were no problem to loosen. But the nuts are starting to look chewed up...I'll be glad to get new lines on. And this time I'll remember to apply anti-sieze.
(I took this picture after step 2 below, my bad)
2) Remove the two m/c lines from the combo valve
Make sure you know which line goes to which port on the combo valve & m/c. You will almost certainly have a hard time getting a flare wrench on the fittings at the combo valve. And even if you can, they are likely crudded to high heaven, and the PO probably did you the solid of rounding them off for you. Well mine did, anyway. The angle grinder wouldn't easily fit, so helloooooo........bolt cutters!
This seemed like an easy way to go, and allows the use of a 6pt socket to remove the stub if you cut it close enough (thanks Mike Romain!). The fluid left in the lines will probably drain out, though the bolt cutters seemed to seal off the end, so the mess was fairly minimal.
3) Remove the Combo Valve
Getting the stubs out is still pretty hard with the valve in place. I was able to get the forward one out of the valve from above, using the air ratchet & about 18" of extensions, but the rear stub was much harder. I daresay impossible. It seems like it will be tremendously easier to yank the entire valve out (and clean it up), and thread in the new lines, so I chose to forgo the struggle & bolt cutter the remaining lines.
Optional: Remove the clutch linkage spring
The spring is about 1" in diameter, and perfectly placed to be a nuisance. I used my drum brake pliers to temporarily remove the spring; it is nowhere near as tight as what you find in the drums. There is a 100% chance I will forget to replace this spring when I put everything back together, and I will cry when I find I have no clutch pedal.
You'll need to remove the wiring to the switch on the top of the valve. There are also two screws that hold the valve to a bracket that mounts to the frame. They seem too small for the mounting holes in the valve, but they thread into the frame correctly(?) so I guess it's all good. Of course, I broke one off, and I'm not sure how to deal with that yet. The frame itself is tapped here; there is no nut welded on the other side, which I find odd. My bracket looked like a bent rectangle of sheet metal....which has gone MIA under the jeep. I seriously can't find it. But it doesn't look like the ones I see on the Morris site (and also I don't understand the need for the pre-bent lines sold with the prop valve kit; my replacement lines fit directly into the valve, as did the ones I'm removing). To be perfectly honest, it's not clear why the bracket is even necessary. Link here: Prop valve kit from Morris
. This is where the valve used to sit on the frame. The clip is from one of the lines from the cannister. The clip bolts through the valve mounting screw.
4) Clean up your combo valve
The PO had painted mine black, and there was so much dirt & grime on top of it, I surely would have contaminated the system trying to blindly put the new lines in. Getting the stubs out was really easy. I put it into the vice, hit it with pb blaster just in case, and used a 6 pt. socket to get everything removed. A few of them were so grimed up that the socket needed a little convincing to go on. Doing this while under the jeep would've been a nightmare. I don't have a before picture of the valve, but here is the after & what my fittings looked like after 36 years of neglect.
If you got curious as to how the combo valve switch works and unscrewed the plastic switch housing, make sure you tighten it down really well, too. If it wasn't leaking there before, do yourself a favor and don't unscrew it. Ask me how I know.
Front left line:
So that's where I'm at today. I need to get that broken screw out, but the exhaust & bellhousing are in the way of getting an easy out on it. I tried to drill on it last night, but didn't have much success. I've never done that before, so it's a figure-out-as-you-go sort of thing (the doctor is currently accepting advice on this topic). The next step after that will be to route the 2 m/c lines and thread them into the valve (but not
the m/c yet
) before I actually mount it back on the frame. Then the fun and games of routing the new lines. I will probably also clean up & re-spray that portion of the frame. There was a lot of crap hiding behind the valve.
Hopefully you find this interesting. I find that writing it out forces me to think about what I've done, which leads me to think about what I'm doing next. Thinking is generally good.
Chapter two, in which we actually install some parts: