Jump to content

Intermittent Braking Ability - 300tdi


Recommended Posts

Hi guys! Need some pointers with a brakes problem on my 90 300tdi please

Typically, the braking potential of my Land Rover has never been one of it's strong points, however after replacing the servo and master cylinder (including bleeding the system) and checking that the vacuum pump still works satisfactorily, I noticed a massive improvement (up from 27% efficiency to a healthier 70% according to the MoT brake tester). This improvement has lasted for approximately 1 month.

However, as with all things Land Rover related, this was not the end of it...

My brakes have reverted to their less than great state just a month or so after. The pedal is very firm (firmer than when everything is working well) although still travels and produces a minimal amount of breaking when pressed hard. This is most frustrating! Occasionally, I get the desired effect but, as you can imagine, this comes as quite a shock.

Any ideas on how to proceed?

Thanks in advance

D

Link to comment
Share on other sites

Cheers for the suggestions chaps!

Hopefully i'll get some time over the weekend to check out the pistons. This seems to have become a problem since this last cold snap so that kind of makes sense. As I said, vacuum pump seems to be working when I check it at tick over but i'll double check that to.

I'll let you know the outcome...

D

Link to comment
Share on other sites

Lasted a whole month? Did the parts come in a blue box by any chance? Seriously, check the servo non-return valve - ease it out of the servo body and pull it off the pipe and make sure it only lets air through towards the vacuum pump. If that isn't Ok ,Bearmach ones are about a tenner. If it is Ok, try sucking on a bit of pipe connected to the servo, if it never gets difficult, maybe its the 'O' ring between the master cyl and the servo - that is supposed to seal. They are about the cheapest bits to check. After that , maybe measure the vacuum if you can, it should ideally be about 0.8 bar - less and its a leak or a duff pump.

Link to comment
Share on other sites

Full marks guys! Dodgy one way valve was the culprit - reckon the cold finished it off. Replaced it with the old valve that I'd (luckily) kept to confirm the fault.

Also, blue box parts are a definite no no for safety critical bits :) - these were Bearmach bits :/

Now on to replacing the exhaust...

D

Link to comment
Share on other sites

  • 3 weeks later...

It's come back! Nooooooo.

Someone else seems to have a similar problem in a later post and the finger is being pointed at a dodgy servo. I'm going to check for cracks/leaks as best I can and try to get a replacement.

I will solve this! With your help :) haha

D

Link to comment
Share on other sites

  • 1 month later...

Just to put this topic to bed, new vacuum pump has solved the problem :)

Checked the servo and master cylinder for leaks etc with no joy. As I have mentioned previously, one way valve was good and vacuum was present (although it transpired that the vacuum was weak). Without the presence of a vacuum gauge, I built a little rig to connect our household's trusty Dyson to the servo to create a guaranteed vacuum and this proved that the rest of the system was OK.

A short time later, new pump fitted and tested with smiles all round!

Thanks for all of your suggestions

D

Link to comment
Share on other sites

Brilliant! Did you find you ran out of extension lead quite quickly when testing? :wacko:

Just to put this topic to bed, new vacuum pump has solved the problem :)

Checked the servo and master cylinder for leaks etc with no joy. As I have mentioned previously, one way valve was good and vacuum was present (although it transpired that the vacuum was weak). Without the presence of a vacuum gauge, I built a little rig to connect our household's trusty Dyson to the servo to create a guaranteed vacuum and this proved that the rest of the system was OK.

A short time later, new pump fitted and tested with smiles all round!

Thanks for all of your suggestions

D

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy