The Triumph Dolomite Club - Discussion Forum

I am running an older Trackerjack set up and have vibration at times, especially frequent heavy braking on track. Its a road car and i don't notice it so much in normal use. Could the discs be warping but cooling to the normal limits as i have used a DTI gauge and run out seems ok. I was thinking of fitting dimpled and grooved discs along with Mintex 1144 pads. Anyone had experience of this on Sierra discs or using the Golf ones. I need something that will cover track and road use.

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Mike

1980 Vermillion Sprint - 174bhp

I remain to be convinced that dimpled, holed, or grooved discs offer anything except looks. The holes or grooves must weaken the structure by providing stress points all over the surface, and they will get clogged with brake dust. However, I can recommend Mintex 1144 pads. I have them on my MGB V8 (large Peugeot ventilated discs and 4-pot calipers on that car) and they give good and progressive stopping from cold. The only downside is they have a tendency to squeal on light application.

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Mike
(1969 MGB GTV8, 1977 Dolomite 1850HL, 1971 MGB roadster now all three on the road)

I'm not having any trouble at all with my TJs on stock pads. Can't remember the make, they were what the factors sent! And as you know, I don't hang about either!

Around 13k miles since I fitted mine and i'm just now thinking about a new set of pads. I will buy something decent, but not 1144s, why spend more when it doesn't appear necessary?

I too am not sanguine about drilled/grooved discs and regard them as "snake oil" for suckers. Any improvement generated (and i'm not convinced there IS any) is too small to notice!

As to your vibe problem, i'd like to see it before I pass judgement! It's POSSIBLE it could be a disc, but generally speaking, once warped, a disc will not recover, not ever! I've seen similar sorts of unwanted vibes from duff inner track control arm bushes. Like I said, i'd like to see/feel it first!

Steve

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'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.

Thanks guys. I had also read some negative stuff on those type of discs so I am happy to keep to stock vented discs from the Sierra. As for the vibration Carl at high speed and hard braking I get quite a violent shake on the steering wheel. Not much felt on the road.
I believe all bushes etc are good but I can check again. Poly bushed all round.

Front wheels are not balanced but running at 70 on the motorway is fine. Could balancing make a difference on braking ?

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Mike

1980 Vermillion Sprint - 174bhp

Last week at the local Triumph owners group meeting a triumph 2000 owner told me he had the same problem a lot of vibration when braking hard and it turned out to be play in one of the suspension ball joints. He advise me that he could not detect it until he had the ball joint out and then it was very little play.

I used to get something similar from time to time on my racecar, different rotors and calipers though. It was either down to wheel bearings or run out on the discs. In the end I would only use Timken bearings and had to tighten them to the point where there was no perceptible play, but at the same time not a trace of binding. Used Castrol HTB (high temperature bearing grease) and shims to enable better adjustment than allowed with just the standard castellated nut. As far as run-out on the disc, I always tried to get as close to zero as possible, even used paper as shims! Checked and adjusted before each race meeting as part of my lengthy checklist. Time consuming, but worth it.
Geoff

Thanks guys. I think I will try and get the disc to Zero as Geoff suggests and also work on those bearings. I know I have found quite a bit of play in the bearing after a track session so I may even have to check half way through the day.

Ball joints seem ok but maybe I need to check off the car. I have new shocks and springs for the front so it will be a good time to strip it all, check and paint.

Fingers crossed.

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Mike

1980 Vermillion Sprint - 174bhp