Make it Stop

While I wait for the slave cylinder to arrive, I can work on getting the braking system functional again. Ordinarily, I would start with the right rear and work my way closer to the brake master cylinder, but in this case, the car is up against the wall on the right side, so it’s a lot easier to start on the left.

The left rear bleeder cracked open with no problem, but there was no fluid at all, even after sitting for a bit. The vacuum bleeder got me no fluid either, so I pulled the brake line off of the caliper. I haven’t done a lot of work on cars of this era, and I’ve never touched anything from Italy before, so maybe this isn’t as weird as I think it is, but the brake plumbing comes off of the master cylinder as a hard line – normal – tracks under the car – normal – and then reaches a proportioning valve at the back of the car, forward of the rear suspension – still normal. Coming out of the prop valve, however, it transitions to soft lines to make the jump to each rear control arm and then returns to a hard line to make the connection to the caliper. That seems weird to me.

That minor digression aside, with the brake line off the caliper, I tried pulling a vacuum and instead of getting brake fluid, the pump held a pretty serious vacuum. To isolate the problem further, I disconnected the rearward brake line from the master and plugged the master with an M10x1.0 bolt and still held a vacuum. So the problem was not likely in the master rebuild job I did, which is good news. Next, I connected the shop air to the brake line that was disconnected from the master and it was unable to push air to the back of the car. Finally, I removed the hard line connection from the rear proportioning valve and was finally able to push air through the brake hard line. It made a mess, but it also got all the old, nasty fluid out of the line, so I’ll take the win.

Surprisingly, the brake plumbing came apart with relative ease. I pulled the hard line off the rest of the way so I could get the soft line out.

You can see in that picture how the soft line connects to the control arm. The prop valve is mounted up on the unibody around and behind the fuel pump.

The soft line was a little bit harder to remove on the proportioning valve side and I didn’t want to risk breaking anything. My solution was to disconnect the right side hose from its hard line caliper connection, take the 10mm mounting bolt out, and remove the valve and hoses from the car as a unit. Once the assembly was out of the car, I put the valve in a vice – okay, I didn’t use a vice, I actually just put it in the hydraulic press to hold it still, but same time – and the hoses came off pretty easily.

As it happens, the car has 6 of these hoses in total, all mounted in the same fashion. One for each rear brake and two for each one in the front. They’re all used to go from a hardline on the car to a hardline that connects to the brake caliper and they’re all the same part number. The hose is about 13″ long and has a male M10x1.0 fitting on each end. I was able to find a source to get new hoses that are the “right” part, but at $25 each plus shipping and only $672 left in my budget, I decided that there had to be a better option. And by better, I absolutely meant cheaper.

As it happens, in the late 70s, Jaguar used an almost identical brake hose. Now theirs had a longer hose in the front than the hose in the rear, but the rear hose is very close in length and they both have M10x1.0 male threads on both ends. I’ve ordered up a pair of the cheapest set from Rock Auto, the Sunsong 2202540 for just under $8.50 each, after the 5% discount and shipping. When they arrive next week, I’ll get to see if they get the job done. I’m hoping that they’re not just good; they’re good enough.

Ordinarily, I would have waited to order those hoses until after I checked the front, but time is getting short, so I decided to go ahead and get those moving and if I need more, I’ll order them up later. Moving to the front left, I was again able to easily crack the bleeders open and started bleeding one of the circuits. Once again, I started with some really nasty fluid, but after a couple pumps with the Mity-Vac, I was starting to drain the reservoir and clean fluid was coming through.

I ran out of time before I got too much farther with that, but that’s confirmation that 25% of the front hoses are in good shape, so I’ll take that win. My next trip over to the shop, I’ll check out the other three circuits and, hopefully, will have good front brakes.