Technical Fiat 850 brake bleeding problem

[Tiller]

I have replaced all four brake pumps in the drum brakes on my 1970 Fiat 850S.
I alsa hade to replace te rear left brake pipe that goes to the pump.

I have now tried to bleed the system without result.
I have tried the regular pump methode and with a vacum bleeder.
No fluid comes through.

Any tips on how to fix this?
The brakes worked before, but the pumps were old and got stuck often.

 

[bugsymike]

I have replaced all four brake pumps in the drum brakes on my 1970 Fiat 850S.
I alsa hade to replace te rear left brake pipe that goes to the pump.

I have now tried to bleed the system without result.
I have tried the regular pump methode and with a vacum bleeder.
No fluid comes through.

Any tips on how to fix this?
The brakes worked before, but the pumps were old and got stuck often.

As a trick that may work on lazy old master cylinders that do not pump very well try removing all bleed valves completely and make sure you top up fully the reservoir, doing this you often do not need to pump the pedal at all.
Just watch for flow and as soon as it starts to come out clean of air refit the bleeders.
Failing that you may need to invest in a pressure bleeder set up.
The trouble with vacuum type set ups is if master cylinder seals are tired they tend to fold in and let air past when using a vacuum.
Let me know how you get on.
Assuming this does the job it may be worth putting a good quality new master cylinder on your shopping list for the future

 

[FPGT72]

As a trick that may work on lazy old master cylinders that do not pump very well try removing all bleed valves completely and make sure you top up fully the reservoir, doing this you often do not need to pump the pedal at all.
Just watch for flow and as soon as it starts to come out clean of air refit the bleeders.
Failing that you may need to invest in a pressure bleeder set up.
The trouble with vacuum type set ups is if master cylinder seals are tired they tend to fold in and let air past when using a vacuum.
Let me know how you get on.
Assuming this does the job it may be worth putting a good quality new master cylinder on your shopping list for the future

The "gravity" bleeding will work on most old cars, pre ABS and computer controls. If the brakes are a single circuit you can do them one at a time, if it is dual you need to know what goes where, or just keep an eye on the fluid level and make a mental note. Usually it ties two different corners together.

A fantastic gizmo is a vacuum bleeding setup, manual or shop air. Just make sure to keep the fluid level up or you start all over again.

I am new here hope I can help.

Oops and do the one farthest away from the master first and work back to the one that is most close.

 

[bugsymike]

The "gravity" bleeding will work on most old cars, pre ABS and computer controls. If the brakes are a single circuit you can do them one at a time, if it is dual you need to know what goes where, or just keep an eye on the fluid level and make a mental note. Usually it ties two different corners together.

A fantastic gizmo is a vacuum bleeding setup, manual or shop air. Just make sure to keep the fluid level up or you start all over again.

I am new here hope I can help.

Oops and do the one farthest away from the master first and work back to the one that is most close.

Some good points and vacuum bleeding setups will work in most cases, though I have found pressure bleeding kits will help where a lazy master cylinder is drawing air from past the back seal, where a vacuum one makes it worse.
I know arguable a new master cylinder is the correct alternative in those situations.
In the dim and distant past "1970s) we found cars like Fords with Girling brakes could be bled with fast pumps of the pedal, but older BMC cars with Lockheed brake systems worked better with slow pumps of the pedal.