Brake Servo

[marc95590]

Hello everyone,

New to this great forum, I hope you can answer my questions.

I have just acquired a 65 BJ8. Although the car is beautiful, the car did not receive any attention for many years. I consider it as a project. I have the repair manual but I'm having some difficulty finding my way around it.

I think I know that the BJ8s are equipped with a brake servo but I can't identify it. Is it correct ? Where is it in the brake servo located under the hood?

Why am I asking for this information? The brake pedal is without any resistance, you have to pump quite a few times to feel resistance and as soon as you stop, the pedal becomes without resistance again. There is liquid Dot 4 in the recipient.

I haven't noticed any leaks...I suppose the brake servo is not working; What do you think?

Thank you for your suggestions
Marc

 

[Bob_Spidell]

Welcome to The Forum, Marc.

There are lots of discussions on brakes and servos on this forum, the search mechanism is pretty good at finding them (it's a frequent topic). But, to answer your question, the servo is bolted to the firewall/scuttle on the passenger side--assuming left-hand drive--below and behind where the oil filter is located; essentially on the front passenger side floorboard (the semi-vertical part). There should be a large--half-inch, I think--vacuum hose going from the rear of the intake manifold that crosses over the engine to the vacuum intake of the servo (in short, follow that hose).

Your lack of brake pedal resistance is most likely due to failed seals in the brake master cylinder and/or the slave cylinders at the wheels. These seals harden and crack over time, esp. if the braking system isn't exercised regularly (and the fluid isn't changed at least every few years). You'll want to thoroughly inspect and repair your braking system before attempting to drive your car. I don't know your supplier situation in France, but the Brits and Germans have some good suppliers. Depending on how much work you want to do replacement of all cylinders is probably the easiest way to go; the cylinders are most likely pitted and sleeving is recommended (honing isn't desirable as the cylinders have a hardened lining). The brake hard lines are likely corroded internally, outright replacement is the surest/safest way to go, but may not be necessary (depending on your comfort level).

When the servo fails typically an internal seal called a 'gland seal' allows brake fluid to be sucked into the intake manifold and you'll get white smoke out of the tailpipe. The servo essentially has an internal master and slave cylinder, they'll likely be in the same condition as the rest of the system. They are rebuildable, but it can be tricky.

 

[marc95590]

Merci Bob for your advice.

I will be checking brake system this WE, starting from the wheel up to the master cylinder. Hopefully, I will be able to define what is wrong.

Regarding the pipe lines, I will change them later. First of all for me, is to be able to move the car to my underground garage....and without brakes, I will let you imagine what can happen

It is a project to kill my spare time during my retirement, so there is a lot of work to be performed and I have time.....

1° ) brake
2°) gas tank and fuel pump (I do not know it the fuel pump is working - no noise when the ignition is ON).

You are right, there are several suppliers in my area (Betaset, Limora, Datch, Moss, etc..) I had to make connection to them at the time I renovated my TR3; so no bad issues regarding spare parts.

Thanks for your support,

Marc