XTREME KARTS XF 1,212 Posted June 12, 2014 Hey fella's, I've got MAJOR brake issues with my XF, i changed the booster as the original one was rooted so i fitted an XG one and the pedal feel was a little better, so i chnaged the front pads, rubber hoses, copper washers, greased up the slides, bled the system and took it for a spin and the pedal almost hits the floor!! So i changed the rear pads, got the pistons back into the calipers (XD calipers they are) bled the brakes again and its still the same. I tried fitting the new rubber hoses i bought but they are the wrong fittings. Though i should point out that the original booster was rooted for a long time and the pedal went worse when i fitted the disc brake diff. Share this post Link to post Share on other sites
PRO250 1,506 Posted June 12, 2014 Somthing ive seen a few times is the master cylinder kills the seal cause its never bween pushed very far down when you undo the bleed valves and push it to the floor it kills the seal, that i think will be your issue. The bore of the master gets shit and corodes you push the piston into all that and the seal dies a painfull death, screaming all the way to the bottom 6 Crazy2287, bear351c, slydog and 3 others reacted to this Share this post Link to post Share on other sites
Banno 479 Posted June 12, 2014 Somthing ive seen a few times is the master cylinder kills the seal cause its never bween pushed very far down when you undo the bleed valves and push it to the floor it kills the seal, that i think will be your issue. The bore of the master gets shit and corodes you push the piston into all that and the seal dies a painfull death, screaming all the way to the bottom Agree with that. Heard a few brake places say the same thing when the master cylinder gets long in the tooth particularly if your rough with the pedal when bleeding. 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
RAWDEAL 222 Posted June 12, 2014 Id had a simmilar problem with the xb.. after i changed diffs, looks like a new master is on the cards 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
XTREME KARTS XF 1,212 Posted June 12, 2014 Cheer's guys, i've got a spare master cylinder here that'll try out first. 1 Outback Jack reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted June 12, 2014 By what you've described, it doesn't sound to me like a master cyl problem. If the pedal drops but stops short of full stroke, then the master cyl is holding. In my experience, a dud cup seal in the master will take up initially and slowly sink all the way to the floor. Sounds more like there's still somehow air in one of the circuits. The only other scenario I can think of where this problem could be caused by the master is if the bore is worn/scored in certain spots and bypassing around the cup. How have you been bleeding it? 1 Outback Jack reacted to this Share this post Link to post Share on other sites
BigCav 464 Posted June 13, 2014 was sounding like it wasnt bled properelly to me aswell, have you got experiance bleeding brakes before? its a semi complicated job especially if your doing it on your own etc Share this post Link to post Share on other sites
XTREME KARTS XF 1,212 Posted June 13, 2014 Yeah i was doing it myself as i couldnt get anyhelp, i'll give it another shot after the W/E Share this post Link to post Share on other sites
RAWDEAL 222 Posted June 13, 2014 Yeah i was doing it myself as i couldnt get anyhelp, i'll give it another shot after the W/E if it helps , i had the same problem, bled the shit outta the brakes lol, diddnt help. the only thing i couldnt try was using the injector style of bleeding them 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
BigCav 464 Posted June 13, 2014 Yeah i was doing it myself as i couldnt get anyhelp, i'll give it another shot after the W/E one of my favourite tools i ever bought was a good pneumatic brake bleeding kit, i personally have an airboy they can vary in price from 100-200 bucks but well worth it, i use it for so many other things, can even drain the engine oil out of the dip stick with it etc 2 XTREME KARTS XF and gerg reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted June 13, 2014 One method I use when bleeding brakes solo is to pump the fluid back up into the master from the callipers by pushing the pistons back one by one. Good time to siphon it out of the reservoir and replace it. Also when pumping the pedal up, don't release too quickly as it will suck air past the piston. 2 XTREME KARTS XF and Outback Jack reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted June 15, 2014 i personally have an airboy they can vary in price from 100-200 bucks but well worth it, i use it for so many other things, can even drain the engine oil out of the dip stick with it etc Excellent all-round tool for bleeding/draining just about anything. I use them at work for bleeding up diesel fuel systems when changing filters, etc. also you can suck out power steer fluid, drain diffs without popping the cover off, empty coolant overflow tanks, the list goes on. A must for any garage I say. 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
XTREME KARTS XF 1,212 Posted July 4, 2014 Well i've noticed this arvo that the pedal has gone soft again, take a look at the front lines and noticed on the left caliper was all wet with brake fluid Share this post Link to post Share on other sites
XTREME KARTS XF 1,212 Posted July 5, 2014 Gave the system a bleed again and the pedal feel has come back, wounder what caused it to go soft again.... Share this post Link to post Share on other sites
SPArKy_Dave 8,888 Posted July 5, 2014 wounder what caused it to go soft again.... the left caliper was all wet with brake fluid Maybe this? ^^^^....... Share this post Link to post Share on other sites
XTREME KARTS XF 1,212 Posted July 5, 2014 LOL dave, i drove to essendon on thursday night and the pedal was fine, friday morning and it was fucked. I check tightened the banjo bolt and YES i REPLACED the coppper washers with NEW ONES. I've always been chasing myself lately with the brakes, never really had an issue with coco tins. 1 SPArKy_Dave reacted to this Share this post Link to post Share on other sites
