brakes (lack of)
Preparing to put my elderly 460 back on the road after an 18 month lay up i find my brakes have left the vehicle. As fluid (or something that was once fluid) remains in system I am suspecting that the seals in the master cylinder have perished.Some vigourous pumping will provide pedal pressure for a while but it soon dissipates .At £90 for a seal kit from MB would I be better to search for a complete cylinder elsewhere? Does anyone know who might make one. Original MB part No. 003-430-0230.I am also suspicious of the servo but am unsure how i can test it. Any help or advice much appriciated, Richard
Sounds like the master but check no fluid around the calipers or drums.
With fluid in the system and pressure on the pedal turn on the engine - you should feel the servo start to work.
Hi purge the entire system by opening the bleed nipple on the rear n/s brake cylinder.... use Universal dot 4 or better.collect contaminated oil in a suitable container you may use 2/3 ltr before the flow is clear tighten the rear nipple the bleed each wheel cylinder / caliper until clear./.. the seals need a clean surface to be able to operate..if still no brakes strip each wheel cylinder and caliper as the pistons may be pitted from the normal ingress of moisture in the brake fluid...if pitted you have no alternative but to replace all...** note if manual transmission the clutch could have the same problem and the difflocks.....
hi Richard there is a diaphragm in the servo unit which may have perished.as per previous thread you should feel the pedal position change when you start the engine...check the vacuum line for leaks but if the ignition switch is stopping the engine then the vacuum should be ok....
Hi
I also have the same problem the g failed it's mot on spongy brakes or lack of brakes.I've bled the whole system through put on new brake cylinders on the back. I've taken the master cylinder apart and the rubbers don't seem to have perished. Does anyone know where i can get a new master cylinder other than mercedes will a 308/208 van master cylinder be the same ?. My g is a 300gd 1985
I'm beginning to run out of ideas anyone HELP please.
Thanks
Hi exactly what did the tester say he was failing them for? do you find them spongy or long pedal or hard to get pedal response? does the pedal fade under your foot? when you bled them did you mix brake fluids?
Hi
The brake pedal goes down to the ground,it will go hard when pumped. The brakes will stop the truck easily. but right at the bottom of the pedal. The pedal also makes a shhh noise when you push it down.
Thanks
Hi if there are no fluid leaks then the rear brakes are not properly adjusted...pull the hand brake up tight and press the brake pedal with the engine running....if there is less travel on the pedal and it does not go all the way to the floor then you need to adjust the rear shoes..at the moment it is taking more than one press of the pedal to close the gap between the shoes and the brake drums...there are threads here on how to adjust the brakes......
Thanks fixwin38
Adjusted the brakes yesterday passed mot today lovely.
Thanks
hmmm, Sounds like rear brake adjustment may be my problem. MOT tester blamed my servo, it seems to be ok though as do master cylinder seals. Will give it a try next. Thanks Richard
JOIN THE GWOA
This website and forum are provided for the benefit of enthusiasts and owners of all Mercedes Benz off road vehicles, in particular the G Wagen. The costs of development, upkeep and provision of the site are met entirely by the annual subscriptions of club members. If you are using the site and are not a member of the G Wagen Owners Association please consider joining. You will have access to areas on the site that are not open to non members, to club trips and meetings and to technical assistance. In addition your contribution (only £25 annually) will help us maintain and develop our website for future users.
Who's new
- Jaffa_JIM_23
- Wrabstar
- GG
- KTMSCANIA22
- 280ge
Hi, i am not sure that the servo is having any effect on the brakes. There is no disernable change when the engine is started. The pump is creating suction although it does not feel particulaly strong. How does the servo turn this into pressure in the brake system? Are they servicable or is it a case of replacement. Thanks, richard