So, I've been trying to get my brakes bled on my '68 142. The front calipers had some sticky pistons, so I replaced them with some recently rebuilt calipers without sticky pistons. The rears are fine, insofar as the pistons move.

(One of) the issue(s) is that the upper bleed port on the left front caliper will not bleed. In fact, I can pull the bleeder nipple all the way out while stepping on the brake pedal, and nothing happens. If I manually push on the pads to retract the upper pistons, fluid comes out of that upper bleeder. So it's not clogged at the bleed port, but it must be clogged somewhere upstream, right? I just can't figure how an obstruction would allow all four pistons to engage the pads, but not allow pressure to get from the MC to that one particular bleed port.

Any thoughts? The car is borderline undriveable, so I really want to get it figured out ASAP.

Thanks,

Tyler

My guess would be your flex hoses need to be replaced.

If you don't have a diagram, hope it helps.
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Antique Swedish Steel 71 142E color V#102

I followed this diagram religiously. Twice. Definitely the most complex brake bleeding procedure I've done.

But after doing some more research, I realized it's got to be the rubber brake lines. Can anyone comment on steel vs. rubber, and where to get them?

Thanks so much,

TF

My recollection is that Rockauto had the rubber brake lines for my 1971 142 and probably had the best price.

I ended up going with braided stainless steel. They were custom made by a local hydraulic specialist shop using the originals as templates. The price was relatively low, around $150 Cdn for the four front lines and two lines to the rear axle.

I don't know that the braided lines will be materially better than the plain jane rubber lines performance wise. They won't suffer from the eventual swelling that seemed to plague some of the Volvo lines (probably not an issue with modern replacements). If you have alloy wheels with large open areas in the wheel disc, the braided lines do impart a lttle bling factor.

I am no mechanic but I agree this sounds like your hoses. As old as they might be, you should probably replace the set. I am pretty sure I got my braided steel flex brake hoses from Planetman. I flat out love them.. Drove around VIR 15 laps...my brakes were fantastic. It really will firm up your pedal.
You probably could get cheaper rubber hoses from someone else if you do not need Hi-performance braking.

There were some forum posts a while back, including discussions about the connection fittings. The hoses have to be professionally made.
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Antique Swedish Steel 71 142E color V#102

Are your brake hoses original, or old? They swell inside over (much) time and don't allow flow. Take the flex line off and see if fluid flows. Often shows up as dragging brakes.
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67 144, 85 740T, 86 740T, 91 945SE, BMW R69S, R60/2