Help with a mystery

Olde faithful · 17th June 2022, 19:47

Rover 75 buddies i need some help on issue that is starting to drive me up the wall

Firstly my R75 DERV Tourer back brake pipe went, no big deal that happens so it went into the garage

when there it had new brake pipes , new caliper and bled

however on return it did this

brake pedal worked as you pressed and after two seconds started to sink to the floor, not entirely to the floor boards but sank slowly. checked and no air in the system, so the garage said it may be a seal on the master cylinder, so i said ok lets get one then so we got one and also placed three new vacuum tubes on the servo also .... wait for it

tried it again with all that done.....two seconds sank again, its not leaking and no air in the system.... so back to the drawing board, this time the garage said the T4 is not talking to the ABS system so may be its now gone as the fluid all drained out from the brake pipe going at this point i said i cannot believe a broken brake pipe would knock out the entire braking system... so in the end i said ok lets get the ABS off my donor which i knew it worked....

placed that on the car... wait for it.... same again two second brake pedal sank slowly, so now i have had brake pipes, three vacuums pipes , ABS system, master cylinder, caliper, and new fluid and brake system bled....

the garage then said the servo must be gone....i said i just cannot believe this, and said hold on lets not change this yet... the two mechs are good guys however we seem to be stumped on this.... can anyone let me know what is going on here, because i fear the worst if we change the servo again nothing will change HELP!!! ROVER 75 buddies

MY BRAKES ARE SLOWLY SINKING? ON THE FOOT BRAKE PEDDLE.

suzublu · 17th June 2022, 19:58

Search for sinking pedal syndrome, ie https://www.the75andztclub.co.uk/for...ad.php?t=63314

xsport · 17th June 2022, 21:45

i thought that like in the MOT quick test , pump up the brake pedal first , then hold it down and start the engine , it should fall . that is for petrol engines. you have diesel so im not sure if they have a vacuum pump system instead. Another diesel owner would know as i have never owned one. !! if the garage boys know their stuff, they would have checked for hose leakage , and that the servo is functioning or not. Its always a bad policy to just exchange parts at random for elimination. Not to mention parts and labour costs. have they run any checks on the servo ? What was their prognosis ? i would certainly ask a few more questions , before opening your wallet again. ...

xsport · 17th June 2022, 21:53

the sinking pedal syndrome is a common topic on here ,especially on automatics. mine has always done this very slightly on my auto,but never been a problem. you seem to have a floppy pedal for another reason. some say that the ABS cannot be purged of air , some say it can with T4.. ..

Arctic · 17th June 2022, 22:14

Have a read of these threads, have the garage done anything like damaging the servo?

https://www.the75andztclub.co.uk/for...d.php?t=318553

If not then look at this thread, taking notice of how Jules does his bleeding.
https://www.the75andztclub.co.uk/for...ad.php?t=63314

Olde faithful · 17th June 2022, 22:19

Quote:

Originally Posted by Arctic

Have a read of these threads, have the garage done anything like damaging the servo?

https://www.the75andztclub.co.uk/for...d.php?t=318553

If not then look at this thread, taking notice of how Jules does his bleeding.
https://www.the75andztclub.co.uk/for...ad.php?t=63314

Thanks Artic, the garage have used T4 to push the air out the ABS and the T4 shows no air however nothing has improved and the 3 vacumn pipes all been replaced and the ABS unit and the Master cylinder only the servo left and to be honest i dont think its that anyway

im stumped also on this

suzublu · 18th June 2022, 21:32

Quote:

Originally Posted by xsport

thats why they dont open them if the nipples are stiff. they would rather chance that than risk a snapped bleed nipple. ..

Ooh, stiff nipples 😁 I must have a lie down 😎

Sent from my SM-A326B using Tapatalk

xsport · 19th June 2022, 10:31

Quote:

Originally Posted by suzublu

Ooh, stiff nipples 😁 I must have a lie down 😎

Sent from my SM-A326B using Tapatalk

no good to anyone on your own ron. ...

xsport · 19th June 2022, 10:35

super pictures Arctic (as always). thankyou. Also i note that this method is done without contamination of any swarth from the process to get inside the brake calliper. nice tip for the torx ..

Drewski · 5th June 2023, 08:41

Quote:

Originally Posted by Olde faithful

MY BRAKES ARE SLOWLY SINKING? ON THE FOOT BRAKE PEDDLE.

Not sure if you still are about but did you get this sorted? I'm having the same problem and it's driving me nuts!

17th June 2022, 19:47	#1
Olde faithful Loves to post ROVER 75 TOURER Join Date: May 2017 Location: BIRMINGHAM GB Posts: 355 Thanks: 27 Thanked 268 Times in 102 Posts	Help with a mystery Rover 75 buddies i need some help on issue that is starting to drive me up the wall Firstly my R75 DERV Tourer back brake pipe went, no big deal that happens so it went into the garage when there it had new brake pipes , new caliper and bled however on return it did this brake pedal worked as you pressed and after two seconds started to sink to the floor, not entirely to the floor boards but sank slowly. checked and no air in the system, so the garage said it may be a seal on the master cylinder, so i said ok lets get one then so we got one and also placed three new vacuum tubes on the servo also .... wait for it tried it again with all that done.....two seconds sank again, its not leaking and no air in the system.... so back to the drawing board, this time the garage said the T4 is not talking to the ABS system so may be its now gone as the fluid all drained out from the brake pipe going at this point i said i cannot believe a broken brake pipe would knock out the entire braking system... so in the end i said ok lets get the ABS off my donor which i knew it worked.... placed that on the car... wait for it.... same again two second brake pedal sank slowly, so now i have had brake pipes, three vacuums pipes , ABS system, master cylinder, caliper, and new fluid and brake system bled.... the garage then said the servo must be gone....i said i just cannot believe this, and said hold on lets not change this yet... the two mechs are good guys however we seem to be stumped on this.... can anyone let me know what is going on here, because i fear the worst if we change the servo again nothing will change HELP!!! ROVER 75 buddies MY BRAKES ARE SLOWLY SINKING? ON THE FOOT BRAKE PEDDLE.

17th June 2022, 22:14	#5
Arctic Give to Learn Freelander 2 Join Date: Aug 2010 Location: West Midlands Posts: 18,717 Thanks: 1,155 Thanked 6,407 Times in 3,874 Posts	Have a read of these threads, have the garage done anything like damaging the servo? https://www.the75andztclub.co.uk/for...d.php?t=318553 If not then look at this thread, taking notice of how Jules does his bleeding. https://www.the75andztclub.co.uk/for...ad.php?t=63314 __________________ Arctic Givology Learn to Give Everything is Achievable ad altiora tendo. Check out our Nano meet dates http://www.midlandsnanomeets.co.uk/ http://www.the75andztclub.co.uk/index.php?thepage=howto " You do the work , we supply the expertise "

17th June 2022, 19:58	#2
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,921 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	Search for sinking pedal syndrome, ie https://www.the75andztclub.co.uk/for...ad.php?t=63314

17th June 2022, 21:45	#3
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,660 Thanks: 358 Thanked 419 Times in 310 Posts	i thought that like in the MOT quick test , pump up the brake pedal first , then hold it down and start the engine , it should fall . that is for petrol engines. you have diesel so im not sure if they have a vacuum pump system instead. Another diesel owner would know as i have never owned one. !! if the garage boys know their stuff, they would have checked for hose leakage , and that the servo is functioning or not. Its always a bad policy to just exchange parts at random for elimination. Not to mention parts and labour costs. have they run any checks on the servo ? What was their prognosis ? i would certainly ask a few more questions , before opening your wallet again. ...

17th June 2022, 21:53	#4
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,660 Thanks: 358 Thanked 419 Times in 310 Posts	the sinking pedal syndrome is a common topic on here ,especially on automatics. mine has always done this very slightly on my auto,but never been a problem. you seem to have a floppy pedal for another reason. some say that the ABS cannot be purged of air , some say it can with T4.. ..

19th June 2022, 10:35	#9
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,660 Thanks: 358 Thanked 419 Times in 310 Posts	super pictures Arctic (as always). thankyou. Also i note that this method is done without contamination of any swarth from the process to get inside the brake calliper. nice tip for the torx ..