• Advertisement
Xclusively Jaguar
SNG Barratt
David Marks Garages
Make a donation to XJ40.com

Soft brakes

Per
Posts: 80
Joined: Thu Jan 01, 2015 7:50 pm

Soft brakes

Postby Per » Wed Aug 29, 2018 7:27 am

All, the brakes are soft and slowly sinking to the floor. Pumping does not change that. When stomping on the pedal with engine off is quickly sinks halfway down and stops there. The master cylinder is new. It does not loose fluid. Hydraulic power circuit (green fluid) is good i.e. no loss of fluid and no warning messages.

My guess is that either there is air trapped somewhere despite bleeding the brakes thoroughly, OR one of the brake hoses is going soft and balooning.

Comments?
1989 3.6 Sovereign

abercanadian
Snr Member
Posts: 1097
Joined: Tue Oct 16, 2012 6:50 am
Location: Vancouver Island

Re: Soft brakes

Postby abercanadian » Wed Aug 29, 2018 9:09 am

My opinion? Air in the system. If all wheels bleed with no air bubbles there can often be air trapped between master cylinder and booster pump.

Try bleeding the line between these two to see if that helps.

Larry
Image
94 XJ40 VDP vin 701729
Oyster Metallic/Doeskin on Aero Alloys
220,000 Kilometers/136,700 Miles
Daily Driver

94 XJ40 SOVEREIGN vin 703632
Diamond Blue Metallic/Barley
111,000 Kilometers/69,000 Miles
Parts Car

NMV 1E
Snr Member
Posts: 722
Joined: Fri Apr 17, 2009 9:26 pm
Location: Lydiate, Merseyside.

Re: Soft brakes

Postby NMV 1E » Wed Aug 29, 2018 10:41 am

Accumulator sphere ? Does this M.Y. have one :?:
Life begins at Forty !... I was born with nothing, I seem to have most of it left.


2006 Baby Blue Hyundai Getz 1.4 CDX, Auto (yes I know, I know, but you'd be surprised, I was !)
1989 White and Navy Blue V.W. Golf Cabriolet (G.T.i.)
1992 Tornado Red V.W. Golf "tintop" 5 door (G.T.i.) For Sale !

Per
Posts: 80
Joined: Thu Jan 01, 2015 7:50 pm

Re: Soft brakes

Postby Per » Thu Aug 30, 2018 9:25 am

Thanks guys, will bleed again focusing on that line. The sphere is good: No problems with the pressure warning associated with a dead sphere. I replaced it around 15 years ago before I sold it and it is still holding up. (As written elsewhere I bought it back nearly 3 years ago and have brought it back to life for my daughter's use.)
1989 3.6 Sovereign

Per
Posts: 80
Joined: Thu Jan 01, 2015 7:50 pm

Re: Soft brakes

Postby Per » Fri Aug 31, 2018 6:12 am

Checking service manual vs some older posts here and elsewhere the answer may be quite simple: The tried and tested bleeding procedure in the service manual is for the non-ABS only. So I will try again pumping the pedal with ignition off 20+ times, then do the front lines, engine on, and then the rears. That is supposed to be the correct procedure for this particular ABS system. Oh well.....
1989 3.6 Sovereign

accoj
Posts: 4
Joined: Sun Jun 25, 2017 2:38 am

Re: Soft brakes

Postby accoj » Fri Aug 31, 2018 7:48 am

Hi Per I had the same trouble my brake pedal kept going to the floor and was leaking green fluid I had them pressure bled and they improved slightly but still felt like I had no power assist at all sort of like driving with drum brakes I checked out the cost of a new system and it was more than the car was worth anyway I did this before I go on the self leveling suspension had been replaced with Bilston shocks anyway I took out the Girling power ram thing and replaced it with a series 3 booster and bypassed the two fluid lines and used the original master cylinder well now my brakes will lock up at speed and the pedal only goes half way down over all it cost me less than $200 about 100 pounds I had to buy an adaptor to fit the two hydraulic lines that went to the Girling booster and I made an adapter plate out of 3 mm steel plate and a second hand series 3 booster a metre of 10mm hose and a fitting to go into the intake manifold around number 5 cylinder and thats it good brakes and very reliable stops every time heres a pic thanks John in Brisbane AustraliaImage[img]


Return to “86-89”

Who is online

Users browsing this forum: No registered users and 1 guest