brake bleeding

[malcmari]

I've just fitted a COMPLETE new braking system, master-cylinder, pipes, hoses, wheel cylinders and brake shoes. and have been bleeding ever since. Have checked all joints for leaks but still keep getting bubbles and the pedal still goes down to the floor
Has anybody had similar experience, any suggestions welcomed   

[Pete126]

you could try this trick from paul harbinson a forum member

"Ok lets go back to basics and try this,sometimes have to do it on the jags.Fill the reservoir tp the top,then,open all the bleed nipples (put something under each wheel to catch fluid).What you do then is go into the house for half an hour (occasionally returning to top up the fluid) and have a cup of tea and a chocolate hob nob.Let gravity do the work."

when all the nipples are dripping fluid tighten them up, Then bleed the normal way starting at the furthest first.

If you use  the search on the menu Above there are quite a few threads on the subject

[ChrisRLewis]

It may be that your brake master cylinder requires bench bleeding?  Do a google for " Brake Master Cylinder Bench Bleeding"

[damon500]

Gravity bleeding is definitely the way to go- done it for years and works a treat. I have never suceeded with pumping the pedal.
Remember though that you won't get a high pedal until you drive the car and the shoes adjust out, once you get a firm pedal then reverse the car backwards and hit the brakes hard then forward and brake again.
You will need to go for a good drive and the more you brake the less travel you will feel in the pedal...
Happy bleeding!

[126bis1997]

These are good suggestions

Never thought of gravity bleeding !

Thanks and cheers for that

PETER

[malcmari]

Thanks for the suggestions, I'll have a go at this "Gravity Bleeding" and I will look into "bench bleeding" the Mater cylinder
Thanks !

[Gadge]

i've had the same problem, so i think i'll be giving that ago too! another idea i heard was to get someone to tap the master cylinder with a spanner to release any trapped air inside whilst pumping the pedal?

[GTMaster]

I've only seen master brake cylinder tapping if it was rotted in... some master brake cylinders have their own bleed valves but these ones don't. Start with the furthest wheel brake cylinder (RHD... so it's rear left) follwed by rear right, front left and front right; the brake cylinders on the rear make up a circuit and the ones on the front are a brake circuit as well.

[1973/126]

 I`m having exactly the same problem and starting to pull my hair out. I've overhauled the brake system on few 126s before but this time is a real nightmare.
 All new wheel cylinders and a new brake master. Have gone through few liters of brake fluid now, and  I`m actually on the second brake master, as I thought it must be something wrong with the master cylinder.
 Tried all sorts of bleeding, but the pedal goes completely to the floor. The brakes actually seem to work, but there is no resistance in the pedal. Also tried too bleed the master cylinder. No visible leaks anywhere and I`m running out of ideas.
 Any suggestions would be appreciated!

[Pete126]

It could be that the shoes are not centralized, Try driving the the car in reverse then stomp on the brake pedal, do the same going forward, do this a couple of times and see if the pedal comes up, also do this with the hand brake and see if that helps.

[Rusty's Uncle]

Could be that the friction pads / self adjustors are not holding the brake shoes in position. So when you pump the pedal the shoes move out towards the drum then just get pulled back by the spring instead of holding in position for the next pump to move them out further. Bleeding the rears with the hand brake on might help. Also if you have rubber flexi pipes fitted and 3 clamps that you can nip onto the pipes then you can isolate one wheel at a time to see if you can get a pedal & braking on that wheel, good luck 

[1973/126]

 Thanks for the advise guys!!! Tried the reverse and slam the brake method, but it didn't work. I decided at the end to use a set of brand new shoes all round. Put everything back together and it worked pretty much straight away without any bleeding. The brakes are nice and sharp now. I might just bleed the system through again to be on the safe side, but I've got a "pedal".
 So looks like it was the brake adjusters after all. MOT day tomorrow

[Rusty's Uncle]

Well done mate & good luck for the MOT
I remember reading about one guy who had the same problem so he left the shoes outside for a while so they rusted then the friction adjustors had something to bite on. Some of those adjustors are fixed on with a circlip so can be removed and are worth keeping.

[124cso]

I have just replaced my master cylinder and it took a lot of bleeding to get things bubble-less. The car system is supposed to be 320cc ? I went thru about 1.1 litres of fluid  to get the bubbles out. Did the whole system in turn about 3 times.
I'm used to 4 wheel power disks so now will have to get used to non assisted teeny drum brakes !!!!