# Lucas Girling brakes



## yardbird

I have a 1987 Ford F700 with front disc brakes and rear drums are Lucas Girling brakes. I recently changed the master cylinder, due to a leak. I was able to bleed the front brakes with no problem. I tried to bleed the rear drum brakes.....I loosened the bleeder on top of the brake chamber and am not able to get any fluid to pass through the bleeder. The master cylinder is full of fluid, I depress the brake pedal and have good brake pressure, but the pedal does not sink when the bleeder is open, nor is the fluid level going down in the master cylinder. I disconnected the brake line above the differential where the single brake line splits to feed both brakes. I did get some brake fluid, but did not depress the brakes to see if there was any pressure. A friend of mine blew compressed air from the divider on top of the differential to the brakes and no air came out of either rear bleeders. he blew compressed air from the passenger side rear bleeder and air came out of the divider and an air and power steering fluid mix came out of the driver's side rear bleeder.

Any advise would be greatly appreciated as I have limited knowledge of this Lucas Girling beast.

Yardbird.


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## mlappin

How long have they been on? Usually only happens on vehicles that's been a real long time since they've been bled but your bleeders can get clogged up. Take em out and clean them with a small drill bit, run it down the center of it then there will be a hole in the bottom 90 degrees to the first one, or just buy new bleeders.


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## rajela

Or just break the tubing nut loose and bleed it there.


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## Blue Duck

Did you you have the engine running, parking brake released, and make sure the power steering level is up were it should be when you tried bleeding them? I have limited experience with Lucas brakes but one thing learned the hard way is what ever you do, don't ever put stop leak stuff in the power steering.


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## mlappin

rajela said:


> Or just break the tubing nut loose and bleed it there.


Yah, but you'll never get all the air out of the wheel cylinders, if it's as picky as our old Dodge 600 was with the dual hydrovac cans, any air quickly equals no brakes.


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## yardbird

We did take the bleeders off and clean them. They were nasty but were unclogged rather easy. The brake fluid and power steering fluid in booster were full. I did have the parking brake engaged. Would it make a difference? Is anyone able to explain why air wouldn't pass through from the divider to the wheel cylinder but an air power steering mixture came from the brake chamber backwards?


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## slowzuki

Some of those old systems before dual splits have safety valves or it may have a load sensing valve with something funky going on.


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## Blue Duck

If I remember right there is a pilot operated check valve somewhere on the back axle or built into the brake cans so if the engine dies and you lose power steering pressure your parking brake won't lock up. That would possibly be why the fliud will only go one way with air pressure. It has been fifteen years since I have worked on these and I don't remember how the parking brake and the regular brakes tie in together so I don't know if it would matter having the parking brake engaged or not. Just throwing out ideas, good luck


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## yardbird

Well....It certainly helps if you open the right bleeders. Found another set of bleeders on the wheel cylinder and bled almost right away. Hauled few overloaded loads of dirt today and had brakes. Thanks to all who gave advice.

Yardbird


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