Guest RobD Posted June 27, 2011 Share Posted June 27, 2011 Hi All, I need some advice on an issue I have with my brakes. My cab is a G reg MK4 MFI. I recently bled all of the fluid out of the system and uprated my front discs and calipers to RS Turbo ones. I also changed the hoses to the Steel braided type. On the rear I fitted new cylinders new pads and again new Steel braided hoses. I filled the system up with new brake fluid and proceeded to "bleed" the system. unfortunately I found a leak on the rear which I quickly sorted, however... I continually bled the system gettting all of the air out of it and so far have have put just over a litre of new fluid through it but I just cannot get a "firm" pedal. Infact it is terrible. When pumping the pedal with all of the bleed nipples shut, I get a certain amount of pressure on the pedal and then this just suddenly seems to disappear and the pedal goes back to the floor. I then bleed it again, pump the pedal and the same thing happens. I get a certain amount of pressure on the pedal and then it suddenly disappears and the pedal goes to the floor very easily and I'm back to square one. I have left the car standing for over 48hours with card underneath all four wheels and it does not appear to be leaking from anywhere... It's driving me nuts! Could it be the master cylinder? I must add that until I "Uprated" the brakes, they were working fine and I never had any issues. I always had a good pedal so to speak. If anyone has had and overcome this problem and can offer any advice I'd be very grateful. Thanks, Rob. Quote Link to comment Share on other sites More sharing options...
allblue Posted June 27, 2011 Share Posted June 27, 2011 (edited) Does your car have ABS? Are you using a pressure bleeding kit such as Gunson's? Csn you describe the procudure you have used to bleed brakes. Edited June 27, 2011 by allblue Quote Link to comment Share on other sites More sharing options...
Guest avul Posted June 27, 2011 Share Posted June 27, 2011 here we go again hi rob i ad this prob a while ago on my mk3, uprated the brakes alround, bleed the system but no pedel! thought i killed the master cylinder so ordered a new 1, but while i was waitin i ad a light bulb moment as i was lookin at the car, the master cylinder is set at an angle, so left the pipe's all connected unbolted the master cylinder frm the servo & pulled it 4ward so that the master cylinder was level, left it 4 an hour & bolted it bak on & hey presto, firm brake pedel. if this doesn't wrk 1st time do the same but leave it over nyt & u should b gd 2 go. regards mark oh while i'm at it the clutch master cylinder on a mondeo is set at the same angle (sum1 didn't think that 1 tho did they ) get a small plastic bottle & a new valve as u get frm ur wheels & make a hole in the bottle top so that the valve can b pulled thro wiv a tight fit, wiv the system bleed pull of the pipe frm the clutch slave cylinder, push in the valve wiv fluid in the bottle & squeeze the bottle & u will hear the air bubble's come up thro the brake master cylinder resivour, pop on the pipe & undo the bleed nipple but do not depress the clutch pedel as gravity will do the job plenty gd enought, job done i did this last wk so know it wrk's as i couldn't get the air out oh & this it is the second time i ad 2 put this on as the site crashed wen i tried 2 reply Quote Link to comment Share on other sites More sharing options...
Guest avul Posted June 27, 2011 Share Posted June 27, 2011 oh & u can gravity bleed just as gd as usin a presure bleed system, as thats all i do. oh & 4got 2 ad 2 things: 1: do not depress the clutch pedel 4 the mondeo, as i did this 1st & it doesn't wrk & u can not force the fuild thro the master cylinder 2: make sure as wiv battery acid 2 go & boil ur kettle & pour a full ketle's worth water over any spill's 2 neutrelise the fuild. Quote Link to comment Share on other sites More sharing options...
Guest cabrst Posted June 28, 2011 Share Posted June 28, 2011 When you did the bleeding, did you raise the car up ore was it standing on the ground Its becouse on the mk4 theres a loadsystem on the rear, and therefor the car need to be bleed while standing on the ground.. Quote Link to comment Share on other sites More sharing options...
Guest RobD Posted June 28, 2011 Share Posted June 28, 2011 Hi, Many thanks for all of your answers. Much appreciated. To answer some of the questions in your replys; The cab does have ABS. We bleed it without using a pressure kit. Just gravity bled as we have done in the past. Three of us bled the system. One pumping the pedal and then depressing it while I bled the brakes and another person keeping the resevoir topped up. I also made sure I bled the brakes in the correct sequence, furthest from the master cylinder first etc. Also the car was bled on the ground. Many thanks for your advice Avul. I'll try doing what you said and unbolt the master cylinder and leave it level overnight and hope that makes a difference. Thanks for taking the trouble to write it out twice. I'll let you know how i get on but probably will not have the time to give it another go until the weekend. Thanks again to all who replied. Rob. Quote Link to comment Share on other sites More sharing options...
Guest avul Posted June 28, 2011 Share Posted June 28, 2011 no probs rob yea keep us posted pls oh just so u know i always gravity bleed on my own wiv out any1 pressin the pedel & it wrks every time regards mark Quote Link to comment Share on other sites More sharing options...
Guest avul Posted July 3, 2011 Share Posted July 3, 2011 hi rob how did u get on m8? mark Quote Link to comment Share on other sites More sharing options...
Guest RobD Posted July 4, 2011 Share Posted July 4, 2011 Hi Mark, Unfortunately I still have the same problem. Bled the system again but still getting a very erratic pedal. Still seems to build a certain amount of pressure and then disapears I'm going to try to find either a new original Ford master cylinder or a repair kit for the one I've got. Thanks for asking though and also for your earlier advice. Once I lay my hands on the above and change / repair the master cylinder I'll let you know if that sorts it out. Thanks, Rob. Quote Link to comment Share on other sites More sharing options...
Guest RobD Posted July 6, 2011 Share Posted July 6, 2011 Hi again, Need some advice please? I need to remove my master cylinder this weekend to fit a repair kit. It seems fairly straight forward regarding unbolting from the servo and un bolting the copper brake pipes etc however I am not sure about the two plastic pipes that are also connected to it. It is a MK4 MFI with ABS and when looking at the master cylinder there are two platic connections on the left hand side of the master cylinder. Has anyone removed these themselves recently? Do they unscrew like the copper pipes? Is there a knack to getting them off without damaging them? Unfortunately I can be like a bull in a china shop at times... Any advice regarding removing the master cylinder and fitting a repair kit as always would be greatly appreciated. Many thanks, Rob Quote Link to comment Share on other sites More sharing options...
gingergman Posted July 6, 2011 Share Posted July 6, 2011 i done this last week and they was just push on/pull off pipes, but unsure if thats how there menna be (car was bodged up) Quote Link to comment Share on other sites More sharing options...
Guest RobD Posted July 6, 2011 Share Posted July 6, 2011 Thanks mate. Quote Link to comment Share on other sites More sharing options...
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