car shudders under breaking

[pitslayer]

right this isnt the usual are my brakes worn thread. let me explain my dads galant. had warped discs and new pads when he bought it, so he put new discs and pads on, everything was fine, then it started shudder, again under breaking...so we changed the discs and pads again, poss faulty parts....was fine again ran them in like before...started shudder again.....so we did the wheel bearings, and discs again. still there, so we did the gearbox bearings new clutch still there.....just had all the ball joints and rubbers done and its still doing it....our mechanic is going to get the brake disc manfacturer down to have a look. and we cant work out, what it is thats doing it....its kind of like you put new discs and pads on then rag them from new dont run them in at all, and warp them within minutes....weve swapped the wheels around, weve had the tracking done, the tyres balanced
anyone, any ideas?

[psbarham]

seized caliper , mine used to do it before i said supersize me :pimp2:

[Nick Mann]

Is it an auto? Does he come to a stop and then keep his foot on the brake pedal?

[pitslayer]

its a manual....weve tryed everything, serviced the calipers etc

[Exbury]

Would probably agree with it sounding like a calliper siezing, say the calliper stays on and drags the pad on the disc. Checks, how hot did the brakes get after normal driving, stuck pads would get very hot. Also, possibility that if you have greased the callipers etc. and they work ok, that the rubber brake line is degrading and causing a blockage, not allowing the fluid to be released from the calliper, hence causing dragging brake pads.

I would try a pair of new lines and replacement callipers, a calliper and disc are pretty straight-forward and shouldn't be that complicated.

Although, just a though, if the wheel bearing was in askew, would the disc be askew too?

[pitslayer]

no it had the problem before we did the bearing...ill take it down...thing is thow the discs arent warping....there fine if your doing normal driving but if your properly using the brakes they judder

[stuey]

ball joint ? dunno if it affects galants but it has on other cars, seems fine most of the time, but shudders on braking.

[andja]

Mine did this with new pads and discs, had to find a place that could machine the discs while they're on the car, most places cant do 4wd's. fixed it up a treat. Dunno if you tried that already but might be worth it!

[pitslayer]

not 4wd/VR4 :(

[RugbyPete]

have you replaced the lines with a different grade fluid? or mixed/topped up with two different types maybe?

[Exbury]

Checked the surfaces of the hub for rust and the runout of the hub?

Are the wheel nut angles the correct angles for the wheels and being progressively tighten to get the wheel perfectly flat on the hub?

Think we are all running out of ideas here!

[Subaru ETA]

ceck the lateral runout of the rotor. make sure it dont have a bent hub... ummm do you drive thru lot of puddles or anything? when the rotor is hot then gets wet it can cause it to warp

[RugbyPete]

oops, wrong thread, ignore me

[pitslayer]

trust me its got nowt to do with puddles, lol my galant is a puddle hopper, and my shudder is hardly noticable...... weve checked near enough everything now, we dont know what it is. be good to find out what it is and get it done so we can get rid of it.

[White Lightning]

I wonder if this is linked to your other thread ??? :thinking:

[Dan_G]

my car was shuddering under braking too..

noticed lower arm front right ball joint was knackered, so changed all front arms... the shudder lessened but was still there under braking...

then changed my rear calipers and the RHS one was seized. not the piston, but the slider bolts. so only the piston side was pushing against the disc causing it to vibrate...

So it might be worthwhile taking off your calipers and making sure all the calipers are sliding freely and re-grease the shafts.

[The Vee]

Rear discs themselves can also cause this, check them for run out along with Dan_G's suggestions. Used to be quite a common problem with 7Gs and to a lesser extent V6 fwd 8Gs. Mine was one of them!!