No brake pedal or gear selection on 76 auto coupe

[Nigel curry]

Hi alli have just put the selector console back into the car and can get no gears and brake pedal goes to the floor when running,but when I switch off engine the brake pedal comes back to normal!! There is very little gear box fluid in gearbox (car is laid up) could this be the problem any thoughts please guys
Confused owner

 

[Oneball]

Youve got a brake fluid leak. Because you’ve got power brakes, when the engine is not running there is no vacuum to operate the booster so it can’t release pressure from the one side of the diaphragm. It therefore feels solid but there’s still no brakes.

If the gearbox doesn’t have enough fluid there won’t be pressure to operate the box.

 

[Nigel curry]

Well a straight forward and seemingly simple answer to the gears thing, and at least I know which direction to go with the brakes thing thanks for that Oneball

 

[Chuffer]

Hi alli have just put the selector console back into the car and can get no gears and brake pedal goes to the floor when running,but when I switch off engine the brake pedal comes back to normal!! There is very little gear box fluid in gearbox (car is laid up) could this be the problem any thoughts please guys
Confused owner .

Is in an auto ? If so I suspect a vacuum problem as both the brakes and auto trans shift solenoid rely on vacuum operation .

 

[Nigel curry]

You might be on to something there chuffer as I have also had the whole dash out and I have fitted vac hoses for headlights,perhaps I got something wrong there or maybe left a hose not connected elsewhere in that maze of stuff behind the dash.I have checked the m/c and all looks good there and no signs of any leaks elsewhere,the thing that’s throwing me is the car was driven down almost 150 miles beforehand and no apparent problems were detected,a leak was found in gearbox area and I totally accept oneballs comments on no gear selection due to not enough fluid in box.Any more thoughts most welcome and I will start to remove dash etc to see if I have cocked something up(oh the joys!!)
Thanks for your time lads

 

[Oneball]

If the brake pedal goes ALL the way to the floor when the engine is running then it is not a vacuum problem.

 

[johng]

Sounds to me that you either have a leak (could be the master cylinder seals as you might not notice that) or you've got air in the system. Have you checked the brake fluid level?

 

[teamzr1]

How about taking a vacuum hose off engine and either connect a smoker or an air compressor at low PSI should be easy to trace
if and where leaks are ?

 

[Nigel curry]

Wow all great ideas lads thanks for your time that’s me sorted for the next month or two
Thanks all nige

 

[bluehot59]

could be master cylinder seals , even if they look ok, sometimes can push past the fluid doing very little, happened on my willwood system even though they bled ok , soon as locked nipples off , pedal dissapeared again, new rear master cylinder sorted it, dont bother with a seal kit , buy the whole master cylinder, easy to fit and sort, gearbox is too low on fluid, top it up and try it , find out where its going aswell , bit of a leak going on somewhere, you could have a vac hose off or split also , but all easy to sort , bleed brakes in the right order