Jump to content

Sticking brakes and Rev limited engine - one problem or two separate problems?


Recommended Posts

Hello chaps.

last week whilst driving at around 55mph, the car seems to be Rev limited to around 2000 rpm.  Jabbing the accelerator and going in and out of od wouldn’t get the revs above 2000.  A slight burning smell then prevailed until everything cleared and the car ran perfectly from that point on.

 

today, while returning from a pleasant 100 mile round trip, my brakes started squeeling.  This didn’t last too long and all was ok for a bit longer until a rattle / knock appeared which felt and sounded like the pads shifting in the calliper.  A short while later, the front brakes had definitely locked on with a very hard brake pedal and the drag on the car was very great when slowing down.  With only a couple of miles till I got home, I carried on driving until a slight burning smell prevailed and then the whole car freed up again.  
 

once in the garage, the brake callipers were both the same temp (and so were the back drums).  Front wheels were tight to spin but the backs were normal.

 

so do you think I have two separate problems or one problem that has affected the engine revving last week and the brakes this week?  Ie  would the servo cause these symptoms?

 

cheers

 

dave

Link to post
Share on other sites

You have a brake problem which I'd definitely fix first. If you want to confirm this throw the car out of gear while you are traveling in top gear and see if it brakes without you touching the pedal.

You may also have a fuel starvation or other engine problem , a leaking servo will increase fuel delivery giving you more power not less-and a high idle speed.

 

Link to post
Share on other sites

Just an update on this.  I’ve stripped down all the brakes and have confirmed that the problem with the brakes sticking isn’t to do with callipers or cylinders.

m/c isn’t leaking but the servo has now started hissing and accelerating the engine when lightly applying the brake. 
 

ive spoken to trbitz and the conclusion drawn is that the servo (at least) is kaput.  It was refurbed about 5 years ago.  Potentially it is ‘hanging on’ and causing brake drag.

Cheers

dave

Link to post
Share on other sites
15 hours ago, aardvark said:

Just an update on this.  I’ve stripped down all the brakes and have confirmed that the problem with the brakes sticking isn’t to do with callipers or cylinders.

m/c isn’t leaking but the servo has now started hissing and accelerating the engine when lightly applying the brake. 
 

ive spoken to trbitz and the conclusion drawn is that the servo (at least) is kaput.  It was refurbed about 5 years ago.  Potentially it is ‘hanging on’ and causing brake drag.

Cheers

dave

Quite probably the use of Silicon fluid has caused the servo to go U/S Ive had the same problem before with them.

Stuart.

Link to post
Share on other sites

Dot 4 used Stuart.  It’s all intermittent at the moment - happened twice in two weeks. 
 

will replace the servo first and see if that fixes it.

 

cheers

 

dave

Link to post
Share on other sites
  • 2 weeks later...

To close this out, I removed the servo and observed that the pushrod could be pulled and pushed and not return properly.  At its worst, the pushrod projected beyond the casing by a couple of mm.  That was enough to keep the brakes on.  The whole pushrod was rough feeling so sometimes it could retract and other times it would stay out.

I changed the servo out and replaced with a new one and the original problem seems to have been solved.

cheers

dave

Link to post
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.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  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.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.