I have already done all four calipers, and a full flush. Brakes are awesome. Driving this morning - the pedal seems real soft. If I pump it, its much firmer. I t seems better as the car is driven more. There is no apparent fluid loss, car stops straight. I picked up a master cylinder - should I replace it ?

Derek A.
87 245

I'm guessing your Master is fine. I think you need to bleed the calipers again.

Mushy is usually air not a the Master. A bad master, as Art said, is a slow sinking pedal as you hold a little pressure on it.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

If you replaced all 4 calipers, did you bleed in the correct sequence as shown in Bentley and Haynes manuals?

And did you check the front (rebuilt?) calipers for mismatched halves? Several instances lately, and it leaves an unbleedable air pocket.
Check this thread for details.

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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

i did mine in march, the pedal was going further down than it should, so first i changed one of the front calipers that leaked a little when i did the pads , that didn't work, so i figured it was the caliper and it was. but you will have to bleed all the calipers, a real pain

Hi Derek,

So you have one 240 and a brand new master that fits 240s. If the pedal sinks as you hold the car at a stop light, replace the master now. If not, replace it when you have the time.
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Art Benstein near Baltimore

The MC has developed internal seal leakages precisely because you have done the other work. Pumping the pedal beyond the range in normal use, such as when bleeding the brakes, moves the pistons and seals over new portions of the barrel which probably were dirty or beginning to rust. This has damaged the seals.
Read the other threads on how to bench bleed a new MC and fit it without needing to rebleed the whole system.