front wheels (brakes?) smoking

[PodOne]

Maybe a stupid question Matt but have you fitted the right pads and are the shims flush to the rear of the pads?

Disc wise are there any high ridges to the outer of inner areas just beyond where the braking surfaces which could be causing them to bind on the edges? If theses areas are corroded try reducing this or if not done already replace the discs as they have a maximal wear limit, too thin and they can crack with heat.

When you fit them you need to push the calliper piston fully back this generally allows you to slide the pads in easily and fit the pins. Then applying the foot brake generally takes up the slack and you should be able to rotate the wheels with minimal drag. "Just about " as you describe seems too tight to me.

Andy

[MC1234]

Thanks Peter and Andy.

Andy, I didn't fit these calipers and pads so I can't be certain that they are the right type. I was told the calipers aren't original and are from Rimmer Bros.

The discs seems to be good as far as I can tell, with no obvious ridges or imperfections.

I suspect I didn't push the pistons back as far as I needed to when refitting the calipers. But I think I would have had to open the bleed screw to do this which I didn't do.

Matt

 

 

[PodOne]

Hi Matt 

No need to open the bleed screw.

You should be able to push the pistons back all the way just make sure there is enough space in MC reservoir to accommodate the expelled fluid. I usually use a small block of  wood and pipe wrench or small G clamp to squeeze the piston until it sits below the calliper pad surface.

When trying to turn the disc is this without the wheels fitted if so when the wheels are fitted are they turning more freely? 

Andy

[charlie74]

Once you have everything back together, don’t forget to pump the pedal a couple of times before you take the car out for a road test…there can be too much “slack” in the calipers if the pistons were pushed completely in to the caliper bore and if you don’t do this your first application might not stop you…

[MC1234]

thanks both. 

Andy, yes the disc doesn't turn freely without the wheels fitted but the wheel does turn more freely once fitted.

[PodOne]

On balance Matt if it's better with the wheels fitted I'd be tempted to go for a drive and bed the pads in. You can in my experience generally feel the rolling resistance reduce as the pads bed in while driving.  I'd just jump out perhaps and check a few times that things aren't getting excessively hot  and smelling of burnt brakes and avoid hammering the brakes too much other than doing a few braking runs from around 50 - 60 down to 20 allowing them to cool a little before the next attempt. Usually feel much better the next day after things have gently cooled.

Just my thoughts others may offer alternative but its worked for me.

Best of luck I hope they are good this tie around.

Andy 

[MC1234]

Thanks Andy, though the pads aren't new so I don't think it's a case of them bedding in as such. I took it for a short drive yesterday and after driving at 50mph for a couple of minutes I started to smell burning so there's something wrong with the set-up I think. It's now booked in with a local mechanic for mid July so hopefully they can find the problem.

Matt

[PodOne]

7 hours ago, MC1234 said:

Thanks Andy, though the pads aren't new so I don't think it's a case of them bedding in as such. I took it for a short drive yesterday and after driving at 50mph for a couple of minutes I started to smell burning so there's something wrong with the set-up I think. It's now booked in with a local mechanic for mid July so hopefully they can find the problem.

Matt

Sorry to hear they are still problematic Matt.

Please feedback. Myself and others would like to hear what the problem was we can then perhaps learn something from your experience.

[KiwiTR6]

This is a long shot and I mentioned it briefly in an earlier post today regarding issues with my car when I purchased it. 

I had exactly the same problem.  Drove 5-10km and the front brakes started to smoke.  Called for helper with a spanner.  Broke open the caliper bleed screws to relieve the pressure and gingerly drove home relying on the park brake.

Credit for identifying my problem goes to NTC.  He suggested the tipping valve in the master cylinder wasn't releasing the fluid and he was exactly right (as he was about other issues I had).  The cylinder had been sleeved with stainless steel but the cut-out for the tipping valve didn't match the original opening and was preventing it from releasing the fluid back to the reservoir (I think that's how it operates).  I very carefully opened the hole up fully and that was the end of that problem.

Yours might be a faulty MC doing the same thing - definitely worth a check!

 

[stuart]

5 hours ago, KiwiTR6 said:

This is a long shot and I mentioned it briefly in an earlier post today regarding issues with my car when I purchased it. 

I had exactly the same problem.  Drove 5-10km and the front brakes started to smoke.  Called for helper with a spanner.  Broke open the caliper bleed screws to relieve the pressure and gingerly drove home relying on the park brake.

Credit for identifying my problem goes to NTC.  He suggested the tipping valve in the master cylinder wasn't releasing the fluid and he was exactly right (as he was about other issues I had).  The cylinder had been sleeved with stainless steel but the cut-out for the tipping valve didn't match the original opening and was preventing it from releasing the fluid back to the reservoir (I think that's how it operates).  I very carefully opened the hole up fully and that was the end of that problem.

Yours might be a faulty MC doing the same thing - definitely worth a check!

 

It was a similar problem with that batch of TRW master cylinders quite a few years ago so it is possible its one from that batch.

Stuart.

[Malbaby]

IMHO...TR6 brake master cylinder's are a bad design anyway.

[MC1234]

I had to wait a while to get a mechanic to look at it but the problem was the master cylinder pushrod. He's adjusted it slightly and bled the brakes and he's confident that's where the problem was. He tested the car but I'll try it on the motorway soon to be fully sure the problem's gone. 

Thanks for the comments and suggestions. It's fair to say I know a lot more about TR6 brakes than I did a few weeks ago!

Matt

[harrytr5]

I made this up but copied it from the net.

Takes all the guess work out of measuring the gap. TRW depth is much deeper than original. I only prefer the original and have that rebuilt by past parts.