Brake Judder

Post by **Packedup** » Fri Apr 18, 2008 6:59 pm

Yes, I have a Minor.

And yes, it needs a bit of fettling (not unexpected).

One of the problems is there's some brake judder, most noticeable at lower speeds. There's also a general feeling of tiredness at the front, but that could be normal, I've been driving a very stiff Metro GTa for the last few months, and my Midget the last few days.

Before I start grovelling around in crud covered underseal inspecting everything, I was wondering what the most likely cause would be? Both sides have had new top and bottom trunions, and so new top trunion bushes (rubber). My guess would be bushes, but would it most likely be tie bar or eye bolt? This car is a cheap and cheerful stop gap while I fix my Metro so would prefer to target the causes rather than just replace everything.

There's also a bit of clunking around the front suspension - On my Midget throwing good suspension corners and recon shocks on fixed that, but again, with the trunions being fairly new is this likely to be shot bushes, or tired shocks?

Post by **bmcecosse** » Fri Apr 18, 2008 7:33 pm

Well yes it could well be the tie-bar rubbers - or the bushes on the inner pivot of the lower arm. Make sure the dampers are nice and secure. But the judder may be the brakes - open them up and inspect!

Post by **Packedup** » Fri Apr 18, 2008 7:34 pm

Forgot to say, on the topic of front brakes - How easy is it to get the J brackets to fit Midget discs? I've got a pair of Midget front hubs etc spare (I know I was supposed to sell them, but still haven't reconned any calipers for myself so I know what's spare and what's not yet!) so as far as I know all I need is the brackets, and new discs/ pads (my spares are pretty worn). It's not something I'd go out of my way to do, but as I've got a fair bit of the kit I'm considering it.

Post by **bmcecosse** » Fri Apr 18, 2008 7:37 pm

I think you may have to make them !

Post by **Packedup** » Fri Apr 18, 2008 7:49 pm

"Bother"

I meant to type how easy is it to get them made, but thinking about it it'd be nice to get them off the shelf after seeing a link to a US site doing them. Me and making such things is not possible, and if it was I still don't think it'd be such a great idea!

Missed the reply about bushes - I've not had chance to really look over things yet, but it'd be nice if it's the tie bar - I've only ever bushed eyebolts with them off the car, and everything else was off too at the time, as it was a ground up reassembly! Don't much fancy having to do them so hoping they're OK...

AFAIK the front brakes were redone not so long ago - The rears almost certainly weren't though as I've discovered the cause of the brake squeal I've been hearing at the back - There's a few thou (or less) material left on the lower rear right shoe! No wonder the pedal goes too far, the poor adjusters have no chance of making up for that. Time to see if the local factors can be haggled down to ESM prices, otherwise it's a few days wait and I don't think I want to drive it with the brakes in that condition

Post by **bigginger** » Fri Apr 18, 2008 7:59 pm

?? ESM are pretty much next day delivery

Moderate away, folks, ifI'm not allowed to say that...

Post by **bmcecosse** » Fri Apr 18, 2008 8:02 pm

I thought it was OK to say GOOD things - but not BAD things!

Post by **bigginger** » Fri Apr 18, 2008 8:05 pm

Different for moderators - we might be seen as "club officials", apparently, and to be seen as the club recommending a supplier. Can't see that I've done anything that might be seen as that, though
a

Post by **Packedup** » Fri Apr 18, 2008 8:26 pm

Good as ESM are, I can't see them making a personal delivery to get shoes here on a weekend!

I'd imagine if I ordered tonight they'd get here Tuesday - If the local factors have the shoes and can be haggled to sensible money (they've become just a tad pricey in the last 12 months

) I can fit them and be driving tomorrow. If they can't be haggled, I can still order from ESM, and get the bits Tuesday, it just means having to depend on a very "endy" Midget or completely (yes, I've killed an A series bottom end...) "endy" Metro for a couple of days.

Post by **bigginger** » Fri Apr 18, 2008 8:28 pm

Fair point - forgot about the w/end

Post by **Packedup** » Sat Apr 19, 2008 2:58 pm

Got the shoes for about £3 more than ESM (but then, with the weight they'd have cost a bit in postage I imagine), so not too bad. Got them on and adjusted up, and went to adjust the fronts - Ran out of adjustment!

Pulled the front left drum - Similar story, lining down to nearly not there and very crazed/ cracked.

Another trip to the factors has resulted in new front shoes, which I'm taking a break (oh the puns) from fitting as I did one and couldn't get the drum back on! Was hoping they would center up so wellied it on and had a once round the block - No chance. I think I'm going to take a little off the ends of the metal on the shoes, should do the job without any safety worries.

It remains to be seen if this cures the judder though, although a new track rod end might help (the left one is just a little sloppy)!

Post by **minor_hickup** » Sat Apr 19, 2008 3:03 pm

As far as making the J-brackets goes. I asked a firm who said they could laser cut them. It would be about £90 each set or something like £20 each if they did a run of ten. Most the cost is in setting up the machines apparently. If 10 people wanted them I could get some made.

Post by **bigginger** » Sat Apr 19, 2008 3:34 pm

Packedup wrote:I did one and couldn't get the drum back on! Was hoping they would center up so wellied it on and had a once round the block

Are you certain that the adjusters were set to minimum/contracted? They're pretty counter intuitive and deceptive - have another look at them

Post by **Packedup** » Sat Apr 19, 2008 3:54 pm

bigginger wrote: Are you certain that the adjusters were set to minimum/contracted? They're pretty counter intuitive and deceptive - have another look at them

Oh yes, they were at minimum - I had a good look at how they work when doing the rears - Cleverness through simplicity really aren't they? Not like the Mini/ Metro ones that are designed to seize up and never work...

After a closer look the radius of the shoes around the adjuster slot were resting on the base of the adjuster brackety bit. Not sure which bit is too big (the metal of the shoe, the lining, the slave cylinders etc), but a bit of gentle Dremmeling of that has seen one side go on, just finished tweaking the other pair and am taking a quick rest from being cold and wet and covered in car grime.

Post by **Packedup** » Sat Apr 19, 2008 3:57 pm

minor_hickup wrote:As far as making the J-brackets goes. I asked a firm who said they could laser cut them. It would be about £90 each set or something like £20 each if they did a run of ten. Most the cost is in setting up the machines apparently. If 10 people wanted them I could get some made.

That's a pretty large difference, seems a run would be barely any pricier than a couple of one off pairs!

Seems Ford or 1500 brakes are in vogue, but I'd certainly be interested if a batch was made

Post by **bmcecosse** » Sat Apr 19, 2008 8:20 pm

Surprised your new shoes wouldn't fit - are you sure the cylinders aren't stuck on slightly ? There's usually plenty of room.

Post by **Packedup** » Sat Apr 19, 2008 8:34 pm

As I "reprofiled" the edges of all 4 shoes I can't be sure the problem was the shoes and not that particular pair of cylinders, but they certainly seemed to retract fully when I pressed on them. There was no way the drum would go back on without a lot of walloping, and I'd have thought that amount of force would be more than enough to unstick the cylinders if it was just a bit of sticking going on.

I'm not saying it's not the cylinders of course, but with a few trail and error fits between grinds I finally got everything together with no problems both sides. There was no binding with the adjusters fully backed off, and I think I've got them all adjusted up quite well - Haven't been for another test drive as after starting what should have been a 20 minute job this morning I was just a bit sick of cold wet windy weather this evening!

I wonder if the new shoes simply had a fraction too much material on them, or the cylinder casting are a little over the spec size (AFAIK they're fairly recent replacements), or the new shoes metal parts weren't quite to correct tolerances. I'm not going to worry about it so long as the car stops well and in a straight line though, I'll just keep a check on pedal travel and check the adjusters regularly

Post by **bmcecosse** » Sun Apr 20, 2008 10:35 am

As long as it's sorted and the brakes are working well!

Post by **Packedup** » Sun Apr 20, 2008 6:24 pm

Hmmm, after more tweaking today they are working. Well might be stretching the truth though.

I'm reasonably happy with the pedal feel and travel now, and the brakes are 100 times better than they were, but... There's a fairly large pull to the left, most noticeable under heavy braking. There's a touch of pulling to the left normally though, so how much is brakes and how much is suspension I don't know. I've had the drum off the front right to watch the cylinders whilst applying the brakes a bit and the rear one moves freely, the front one seems a little more sluggish. It's not stuck, it just seems to lag behind the other one. I certainly wouldn't have thought it was poor enough to make any difference when actually driving.

I think one of the next plans is to rebush the tie bars and torsion bars, from what I can see the torsion bar isn't in the middle of the eye bolt on the drivers side (didn't check the passenger) and there's some odd rattles and clunks that seem to be coming from around the chassis rail.

So as far as the shoes are concerned I think it's job done, I think the cylinders are OK, but there's still some judder and general not rightness that's looking very much like bushes (and hopefully not dampers as well/ instead). Somehow I don't think doing the eye bolt ones is going to be quite as pleasant as it was on the pickup, where everything was nice and clean and painted and ready to just put together...

Post by **bmcecosse** » Sun Apr 20, 2008 6:34 pm

You will find that if one shoe is 'binding' on the drum it quickly heats up and fades - then the braking becomes unbalanced because that shoe is not doing it's share. So - try taking it for a short run with minimal braking - and then feel the drums to see if one is hotter than the other.