Spongey brake pedal

[Portuguy]

After having a new master cylinder and two rear cylinders fitted to the rear inboard drum brake system ,complete flush out and new fluid , the brakes feel spongey unlike before when the car stopped dead with a firm pedal . The reason for the repair was a jammed cylinder piston and high time to repace the fluid . I should take it back and ask to have it sorted but the garage really tried hard to bleed the brakes , even using a home made pump to send air back to reservoir.
I was wondering if by mistake the rear drums got switched over and dont like their adopted shoes .?
Any ideas welcome . Quite a bit pedal travel , better on second press.
Shoes not fully centralised before assembly ?
Still air in system ?but where?
Cheers Aidan

[callum]

Aiden, If you pump the pedal quickly, does it feel better and firm up?

It may be the rear cylinder dust covers are pulling the pistons back in again.

replace the covers with the ones from the old brake cylinders.

Rgrds
Callum

[Geoff Ryall-Harvey]

Daft question.... are you using the right brake fluid? Disc braked 2CVs used LHM and not DOT 3. They don't mix and even after draining off all the LHM you can't replace it with DOT3. I would guess that, in a new system, you could probably use DOT 5 silicone fluid but given that it's more expensive than LHM and still hydroscopic I don't know if it would be worth bothering.

I may be insulting your intelligence here but it is a mistake that lots of people new to 2CVs have made. I used to get given cars that had been topped off with DOT3 by inexperienced owners. Back in the day the cost of replacing seals and/or master cylinders was vastly in excess of the value of a lot of 2CVs.

[Portuguy]

Hi Callum and Geoff, im keeping you busy!! Thanks again .
( Callum):When i pump pedal it still travels quite a bit and eventually feels firmer but by that time the car has travelled, some. Today i heard shuddering noises from rear shoes where the new cylinders were fitted.i thought they momentarily locked as the engine nearly stalled. The front were quiet and seemed ineffective . The front brakes havent been touched as far as i know. The cylinders seem fairly recent and not old by their appearance and not leaking fluid.
It appears the reservoir is situated ever so slightly lower in position than the master cylinder. Maybe an airlock at that point?
(Geoff: )The brake system was identified as Dot 3 or maybe four because of the four drum brakes and no green signs or markings . Yes someone , before me could have topped up with LHM , but they were very familiar with 2cv,s. I did wonder about this. Strangely they did say on the telephone , " i think its LHM "but nothing points to this , so i had a new Master cylinder fitted and the two rear cylinders and it got a good clean out.the fluid had been murky but is now looking like Roibush tea. I still have the old Master Cylinder.im a gatherer.
Is there much difference between dot three and four?
If i can give the garage any clues to go on it would be useful . Its not everyday they have a car like this in an Algarve village.It goes back in tomorrow .

[Geoff Ryall-Harvey]

An airlock sounds likely. They could try power bleeding.

[Portuguy]

Thanks Geoff , seems to be solved after dismantling front drums and cleaning out everything and re adjusting all shoes for umteenth time and re bleeding with some back pressure . Much better now thanks Aidan