early and late brake compatibility?

[CraigB]

I am helping someone with a 74 240d and using parts from 73 280. Car had seized calipers and then trying to bleed, piston appears to be stuck in the master..... lessen to be learned, just to the lot!

Anyway, quickly learned that front calipers are different between the two. Then I rebuilt the 280 calipers at home, took them to put on the car today and while I am sure piston size is the same, then inlet to calipers is different. 74 has a female/male flex line going into back of caliper, 73 has an inlet up high on the caliper and a short pipe down to the centre of caliper at similar position, but to a female /female flex hose. Is anyone aware of any issues of just fitting the 280 ones with a new flex lines?

[John Green]

74 has a female/male flex line going into back of caliper, 73 has an inlet up high on the caliper and a short pipe down to the centre of caliper at similar position, but to a female /female flex hose. Is anyone aware of any issues of just fitting the 280 ones with a new flex lines?

Do you have any pictures? That sounds very odd. Whilst there were a number of a differant calier options across the W114/115 range they all have a brake hose that runs though a bracket off the stub axle and into the middle of the caliper

[CraigB]

Just reread my post..... crucial info - I am talking about the rear calipers. The 280 has a bracket attached to the mounting bolt lock plate and a short hard line runs from there to gop of caliper. Then the female to female flex between that and the hard line from master. Later 240d has calipers that look like W126 with flex line straight into back of caliper. The earlier 280 ones are on the car that isn't here, can take a photo of old ones later

So looking for solution from this point, I would just like to get a couple of new F to F flex lines and run those 280 calipers I have rebuilt. Just trying to work out if any compatibility issues.

[John Green]

Rears do have variants, three to be precise.

1) the flexible hose is between the inner sill and the rear subframe mount with a steel pipe to the caliper
2) f>f flexible hose that comes off the chassis above the caliper location and then goes to a steel pipe that goes into the top of the caliper
3) f>m flexible hose as above, but the hose just goes striaght into the caliper

Sounds like you have option 2 and need A126 428 05 35 to fix the issue.

[CraigB]

Fantastic, thanks John. And piston sizes same? I think the were all pretty much the same except a bit smaller in the later W108 but then back to all being 38mm - and therefore should work fine.

[John Green]

yes, all 38mm