Getting brakes working again

[RedMF40]

I’m working on my ‘66 Citroën and need to get the brakes working. It was parked for at least 20 years before I purchased.

I pulled both rear drums. Brakes and related parts look new.

I opened both bleeders, not even a dribble. Pedal feels very hard. Master is full of fluid and actually looks clean.

I understand how the system works, it’s a typical old car with drum brakes. But I don’t know the things I should check now to get brake pressure. Attached is a photo I grabbed from the web because it looks much better than my car. Thanks in advance for any suggestions.
Gerrit

 

[Vito]

Is it possible a line is blocked with rust or other debris? Don't know much about French made automobiles.

Vito

 

[RedMF40]

Is it possible a line is blocked with rust or other debris? Don't know much about French made automobiles.

Vito

Could be. The setup looks like any other old car with hydraulic brakes. Some hoses and some rigid steel lines. Maybe disconnect the master and see if I can get any action when I press the pedal.

 

[Gambles]

I’m not there to look at it or get any clues, but with the car at 60 years old, I’d be very leery of the brake lines and especially the rubber lines internally flaking off and acting as a one way valve. Loosening a few selected brake lines should help investigate this thought.

 

[RedMF40]

I’m not there to look at it or get any clues, but with the car at 60 years old, I’d be very leery of the brake lines and especially the rubber lines internally flaking off and acting as a one way valve. Loosening a few selected brake lines should help investigate this thought.

Thanks, I’ll check things over when I have more time.

 

[MarkB_MI]

Hmm. A '66 model, if made to pass US specs, would have dual braking systems. If that's the case, then there should be a proportioning valve somewhere. Those are prone to sticking; I'd check and see if you can get anything out the front bleeders.

 

[Steve in VA]

I’m not there to look at it or get any clues, but with the car at 60 years old, I’d be very leery of the brake lines and especially the rubber lines internally flaking off and acting as a one way valve. Loosening a few selected brake lines should help investigate this thought.

I agree with you. Those flex lines are very likely shot.
It is also possible that incompatible fluids have been added years ago.

 

[Ericp351]

Hmm. A '66 model, if made to pass US specs, would have dual braking systems. If that's the case, then there should be a proportioning valve somewhere. Those are prone to sticking; I'd check and see if you can get anything out the front bleeders.

No. 1966 was single pot master cylinder. I have a couple 66 cars, couple 65,s also. Also, no disks equal no prop vlv. At 11 or less horse power this guy is free to adapt go cart parts.

 

[Gambles]

Hmm. A '66 model, if made to pass US specs, would have dual braking systems.

Hmm. A '66 model, if made to pass US specs, would have dual braking systems.

As posted, the ‘67 model years had the mandatory dual master cylinder. My first car, a ‘66 Mustang, had the single master cylinder. The dual master cylinder is a worthy upgrade.

 

[Ericp351]

If you are serious about this thing sugest... find out what, if any rebuild kits exist. Mast cyl, wheel cylinders, etc. Confirm fluid type. If not dot3, assume contaminated. Vintage and europe sugests mineral oil.. Check master cyl. Old, non French, had bleaders. Start at mast cyl. Blead, leak check, rebuild as reqd. Remove and easily bench bleed if reqd. . NO. 3 PHILIPS driver and a vice all ya really need. Then leak check all. Then repair each stuck or leaking wheel cyl. Basic stuff. Lube each pedal pivot and shoe pin.

 

[showcrop]

It appears that some new brake lines are in your future. I replaced most of them in an old car a few years ago. I used copper nickle. It is very good to work with compared to steel. You will need a flaring tool. You will want early on to determine what thread the fittings are.

 

[Bob NY]

It is also possible that the pistons in the wheel cylinders are stuck/rusted in place.

 

[Steve in VA]

It is also possible that the pistons in the wheel cylinders are stuck/rusted in place.

Seen that. Actually had a rover where the wheel cylinders were packed with sand. How? Can't imagine. Those were write-off.

 

[RedMF40]

Thanks for the replies, will open up the brake system and see where I’m clogged. Good chance I’ll be calling my parts specialist in Seattle with another order. I’ll come back with any updates. Thanks again.
Gerrit

 

[Steve in VA]

Thanks for the replies, will open up the brake system and see where I’m clogged. Good chance I’ll be calling my parts specialist in Seattle with another order. I’ll come back with any updates. Thanks again.
Gerrit

Something to consider. When I did the 52 MG every thing was apart including master cyl and all new lines and rebuild cylinders. That completely purged any fluid and I went to DOT 5 to avoid water while sitting for long periods. Old Mister Rattly Bones is the 56 Land Rover and I stayed with DOT 3.
You shouldn't mix 3 and 5, but you may already know that.

 

[RedMF40]

Something to consider. When I did the 52 MG every thing was apart including master cyl and all new lines and rebuild cylinders. That completely purged any fluid and I went to DOT 5 to avoid water while sitting for long periods. Old Mister Rattly Bones is the 56 Land Rover and I stayed with DOT 3.
You shouldn't mix 3 and 5, but you may already know that.

Yes, I did know about possible problems mixing brake fluids. Thanks for the reminder. I forget what it’s called but the shop manual I have mentions some strange brake fluid name but when I checked it’s compatible with DOT 3 or 4. I’m sure I’ll end up purging the whole system.