introducing myself and first problem with the brakes

[szyki]

Hello Everyone,
I'm new here. Thank you for accepting on Forum.
Just bought an honest looking 3.6 Daimler, which spent 18 years with its previous owner.

My First issue is regarding the brakes.

You need to pump the pedal all the time to make the Jag brake.
Any ideas, what could that be? Brake pump or maybe booster?
I've read, brakes are connected with the sls.
Can it affect brakes in such a way?
Thank you,
Simon.

[M-e-l-l-o-w]

My guess would be a problem with the master cylinder or the pressure sphere or both! But that is just a guess, it could be a badly warped disk, sized calliper even a brake hose bulging or braking down inside and acting as a valve! In fact there are a number of things it could be.

It is difficult to diagnose over the internet but the following will help a lot.

First let us know the first three numbers of the numbers at the end of VIN number to give us the model year. You can add this to your forum signature as I have done below. There is no need for the full number. This will help a lot as there are many changes depending on the VIN numbers.

Is the pedal hard or soft? Does it go down to the floor on the first application and need to be pumped up?

Next when stationary with the engine running apply normal pressure to the brake for about 30 to 40 seconds. Does the pedal remain firm or does it slowly sink away down to the floor?

Next when braking gently at speed does the pedal shudder and/or the steering vibrate?

Mellow

[szyki]

Thank you Mellow for the advice.
Just updated my signature.

The pedal is soft and goes all the way to the floor on the first Application.
If you pump It, It starts to brake even not too badly.

Honestly, I didn't Check, if the pedal goes down, when applying the brakes for longer when stationary. Will do that probably tomorrow evening, when I get to the garage.

When braking from a speed, I didnt notice any other vibrations or anything. It just didn't want to stop, if you don't pump It.

Thanks,

[M-e-l-l-o-w]

Well for a start I think 559xxx vin number is a 1989 model year car! As far as I know 1989 MY cars started to be made as early as June 1988 at vin 556851 and finished in September 1989 at 594575 with the last 3.6L car. But I could be wrong.

You will need the VIN number when purchasing parts as they are not all the same.


Mellow

[Eddie_6505]

Could be any manner of things. All part of the fun of owning an early car. I've been having a bit of trouble with mine lately. This thread has a really helpful picture from the manual to help you understand the system: viewtopic.php?t=996807

Unfortunately probelms with this are quite hard to diagnose and can be costly to repair. Hope that doesn't put you off though! It sounds like you're car is having trouble building up the hydraulic pressure. Hopefully someone can correct me if I'm wrong but I think if you run the car for a bit to build up pressure then switch it off then turn ignition back on and pump the pedal a few times until the low brake pressure warning comes on, you should get 4-5 pumps before you get the warning. Less than that suggests the sphere is running low on charge. Other people have had luck with a simple brake fluid change. Does you're sls work at all?

Hope that helps!

[Per]

These cars are not hard to diagnose at all IMHO.

Being some time ago I assume you have sorted your braking problem? If not, have you checked the reservoir toward the RH front of the engine bay with a sight glass on top? Is it red? If so the LHM oil level is low and the system is struggling with air in the loop. Is the problem getting worse? Any green fluid dripping? If neither of the former, as mentioned the pressure accumulator (the black sphere toward the RH rear of the engine bay) is dud. Go for a new one (3rd party due to price), not one of the "remanufactured" ones.