SupraP-Z Posted June 8, 2015 Share Posted June 8, 2015 (edited) Hi All, Over the weekend i changed the front discs and pads on an old 2001 plate toyota previa. What a b@st@rd those bolts were to get off! The pads were completely fooked, down to the bare metal as were the discs. The guy had ordered pads from Euro car parts, which were slightly too big in the "ears" where it slides along the clips. So i had to grind these down, and then they moved freely with minimal play vertically. Cleaned everything thoroughly. Copper greased the metal on metal parts (only a tad) put the shims back (some didnt even fit because of the thickness of the new pads) Pushed the piston back into its bore (it was stuck fast, and i used a big g clamp with an old brake pad on the top and a heavy bar to turn the handle on the clamp, released the piston and put it back in its bore), hammered off the old discs, stuck the new ones on, used red grease on the slider pins and put it all back together. I did not let any air into the system, i left the bleed nipple and flexi hose connection alone. Now before i touched this system, the brakes worked really well surprisingly, really good immediate bite. After i changed the pads and discs there is a spongeyness to the feel and you have to push the pedal very hard to get any bite out of it. So i bled the brakes, old fluid wasnt as nasty as i thought it would be...used the two man method and didnt let any air back into the system as i had the end of the line that was connected to the nipple in fresh brake fluid. Few bits of dirt came out and i pushed fresh fluid through the system. No difference whatsoever? Have i done something wrong? The pads could only go in one way. A few things that im thinking may be causing this, but i dont know for sure: 1). There is one shim missing from one side because it wouldnt fit, surely this wouldnt make a difference? its less than 1mm thick 2). The brake pads were not original parts and the ears were modified slightly to fit 3). Have i disturbed the master cylinder seals or anything of the sort by releasing that stuck piston or pushing the rest of the pistons back into their bore? (I had the cap off...but now have read you are supposed to crack open the bleed nipple?! 4) The back pads and discs have been left alone, apart from being bled. The discs are fine, but the pads are halfway through their life. 5) One of the old pads had a metal spring clip on it (might have been the wear indicator) the new one had nothing of the sort 6). Upon removal of old brake pads there were no retaining clips on them whatsoever, no holes on the new pads for them to go on either What should i be checking for? Any help would be appreciated as i need to sort this out! Edited June 8, 2015 by SupraP-Z (see edit history) Quote Link to comment Share on other sites More sharing options...
stevie_b Posted June 8, 2015 Share Posted June 8, 2015 You probably know this already, but when you fit new pads they usually take a good few miles to bed in. Before that happens, braking performance will feel poor. *edit: my suggestion above wouldn't help with a low brake pedal, so the cause is probably something else. Quote Link to comment Share on other sites More sharing options...
SupraP-Z Posted June 8, 2015 Author Share Posted June 8, 2015 I should probably change the title...the brake pedal isnt low, its just the bite of it. You have to push it down very far before it bites, and even then the braking performance isnt very good either! I do know you have to bed the pads and discs in but the car has apparently covered around 400 miles since its been done, i was surprised as ive never had that happen to me. Just wondering what the cause is? Quote Link to comment Share on other sites More sharing options...
walkerstrider Posted June 8, 2015 Share Posted June 8, 2015 Bleed and bleed again, till it sorts it. Have you used correct rate fluid? Quote Link to comment Share on other sites More sharing options...
SupraP-Z Posted June 9, 2015 Author Share Posted June 9, 2015 Bleeding is sooooo long! argh. Yes mate, well i used normal dot 4, it says use dot 3 fluid...but this is a 2001 plate toyota we are talking about. The pedal was a bit spongey with the original fluid inside before i pushed new fluid through. I guess ill keep bleeding it till it gets better then Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 12, 2015 Share Posted June 12, 2015 Vacuum bleed it Quote Link to comment Share on other sites More sharing options...
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