Brake servo failure

[Berlingo2CV]

I think we have a brake servo failure (reduced braking, only working with extreme force on the pedal - a bit like driving a very old drum brake car). Local mechanic suggested servo or master cylinder but says that he can't get a servo for at least 3 weeks. In my experience a master cylinder failure  would more likely be poor braking unless pumping , rather than lots of force. 

Has anyone purchased a servo recently and if so where? The few I turned up were £200-£300 which seems a bit steep. Not my car btw, my daughter's,  a 2007 1.4 with LPG.  

Rob

[brodfather11]

Check If you are getting a vacuum at the servo pipe which works the servo. It should pull out of the servo unit. The vacuum is supplied by the pump on the cylinder head.
If the pump is u/s then no vacuum and poor brakes.
If one of the brake circuits is not working then poor brakes. If the brake fluid is down then possible fluid leak and only one circuit working.

The servo units are quite reliable , never had a duff one yet or ever had to change one.
A scrap dealer will no doubt have a serviceable one cheap and may come with master cylinder attached

[smutts]

Check the hose isn't split & leaking vacuum.
(Oxymoron? Can you leak something that isn't there?)
This would also cause a lumpy erratic idle.

[Berlingo2CV]

Checking would be so much easier if the car wasn't 120 miles away!! I will look for some pics and try and talk her through the process. Last time we did this was to bodge the gear selector rods enough to get the car driving! I think we may have a Friday afternoon car!!

[Berlingo2CV]

It's definitely the servo or the Master cylinder. Servo test fails, vacuum working. Probably due to putting steering fluid in error and then quickly removing it - damage to seals??

Looking for a used servo and master cylinder online. Will it be the same one as used in the diesels of that year, or would it be specific to the 1.4 petrol only which would make it harder to find? Can anyone recommend particular sources for this type of part?