13 replies to this topic

[Spitz]

Car is a 62 Traveller...up graded to twin leading before my possession.  Tin can master cylinder

 

I recently replaced all shoes, hoses, some hard lines and all wheel cylinders.

Installed drums and adjusted brakes.

Bled, bled, bled...fill cylinder, bled bled, fill cylinder etc. etc. ( level was never too low )

 

The brakes work....but pedal goes near to the floor on first push.  Practical driving consists of several pumps for a good stop.

 

Is this a sign my master cylinder is pooched?  No idea of it's age, but all brake hoses were very old...one front had collapsed and was causing brake to stay on....hence the brake job

 

( first one to suggest discs goes straight to bed with no supper )

 

Thanks

[cal844]

Chase the air from the master cylinder to the cylinders by cracking each union then getting someone to pump the pedal then close the nipple with the pedal down.

Bleed in the correct order.

If you can't get a pedal then I'd look at clamping the flex hoses then testing the pedal once each is clamped

Edited by cal844, 20 May 2019 - 04:03 PM.

[Rorf]

You replaced all the wheel cylinders but didn't even open up the ,master cylinder

 

Its a pain but I would remove the master cylinder and if the bore is still in good condition then replace all the seals (kits available). But judging from the cars age I would suspect it is fubar.

 

Before bleeding adjust the brake shoes all the way.

[cal844]

You replaced all the wheel cylinders but didn't even open up the ,master cylinder

Its a pain but I would remove the master cylinder and if the bore is still in good condition then replace all the seals (kits available). But judging from the cars age I would suspect it is fubar.

Before bleeding adjust the brake shoes all the way.

I do agree with you on this, however it would be worth trying to get pedal better before spending money

Try adjusting the brakes so the drums can't rotate by hand. Then chase bleed from the master cylinder to the wheels.

If you still don't have any joy I'd now

Clamp a flex
Stab brake pedal (any improvement?)

Clamp the next flex
Stab the brake pedal, the pedal may well be higher but keep repeating the above, if you have all 4 flex pipes clamped with no improvement you have an issue somewhere

[Spitz]

I've been bleeding from LR first then RR, FR and FL last....... farthest to nearest

 

So if I were to clap off all hoses at once.....and the pedal moves..... master cyl issue?

[Gr4h4m]

Have only worked on older minis but when I have had a bad mc you could feel fluid on the pedal.

[Rorf]

Also critical when bleeding to ensure master cylinder topped to the brim - tin ones difficult to see the level so these transparent extenders are the answer.

 

Check too that there are no leaks, sure you used new copper washers?

[Spitz]

Update....  ( and yes, master was always topped ).

 

I went in and adjusted each wheel a little better.  top front adjuster was seized...so that helped.  One rear took a couple of flats.

Car stops very evenly.....but pedal is still pretty low.  I fear if I adjust any more than I have....I'll have some pretty warm drums!

Front adjusters are being adjusted correctly in the direction of tyre rotation.  All are installed correctly.
A sign of a little air still in there??   A couple of presses and pedal is hard.....and holds pressure.

 

Thanks

[Twincam]

Try pumping up the brakes then leaving the pedal down over night (use a block of wood against the cross member) and then give it a quick bleed the following day.

[KRM_Simon]

What he meant by adjusting the brakes up, do it “too far” so that you can’t actually turn the drums, just while bleeding. My understanding being, a lot of the bleed screws on drums are at the bottom of the cylinder so not ideal for removing air at the top. By adjusting them up fully you can push more fluid through and out the bleed screw without it also pushing the shoes outwards. When this is done, wind the adjustment back off and then set them as you normally would for the road. Sounds like air if you can pump up to a solid pedal and it holds pressure.

[Mini Manannán]

Has yours got he dreaded FAM7821 fitted?  http://www.minispare.../FAM7821 .aspx   After doing the all the above for months I replaced my FAM7821 with a brake proportioning valve - this one: http://www.mcgillmot...knob-type-677/   It made all the difference.

[Spitz]

No....don't have that valve

[Spitz]

So it seems I may have fitted the wrong rear cylinders.

I put in 3/4"  This is a single line system....aparantly I should use 5/8"

[cal844]

Yes that sounds correct