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Brake drums won't go back on.......
Posted: 18 Jul 2017, 19:58
by Winchweight
So, I originally posted this on FB, but I'm being stuffed by the drums. So, here's the situation:
The van is a 16" Syncro Doka.
The pads, springs, adjusters have all been replaced with like for like quality parts from BW. Each part has been compared against the original part and found to be identical. Each part has been fitted exactly as per the original fitting, confirmed with wiki and Bentley images.
The drums have no lip, the handbrake is free moving and released at the compensator. The adjuster is fully backed off.
But, despite everything neither drum on either side fitted easily. Only the offside has fitted, but it was a struggle and after hours of adjustment it slipped on. The near side is still defeating me. I even tried a brand new drum, but it didn't make any difference.
Is there any trick or tip, to getting them on?
Re: Brake drums won't go back on.......
Posted: 18 Jul 2017, 21:10
by windy
I noticed when I replaced a brake cylinder on my 14" syncro that the old cylinder didn't push the shoes apart as much at rest as the new cylinder, so maybe thats an area to look into?
Re: Brake drums won't go back on.......
Posted: 18 Jul 2017, 21:12
by Winchweight
I haven't touched the cylinders, but I'll have a look.
Re: Brake drums won't go back on.......
Posted: 18 Jul 2017, 21:20
by windy
Maybe your existing cylinders were ok with worn shoes but not with new?
I believe there is quite a bit of variation between different makes of brake cylinder, plus some have a light spring between the plungers to keep them in contact with the shoes, some don't.
Re: Brake drums won't go back on.......
Posted: 18 Jul 2017, 22:09
by Oldiebut goodie
Undo your bleed nipple so that you can push the brake cylinder pistons back in, they are most probably too far out. They are sitting where worn shoes sat!
( Facebook doesn't cut the mustard unless you want to know what chintz curtains suit your van

)
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 07:07
by bigherb
Have you centred the shoes?
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 09:12
by NicBeeee
Or if the nipple is seized take the cap off the reservoir and squeeze each side of the cylinder
Sent from my F3111 using Tapatalk
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 09:17
by Winchweight
Thanks guys. The new shoes areTRW and I have new cylinders I could fit. I already tried removing the reservoir cap and squeezing but it made no difference.
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 09:17
by Winchweight
bigherb wrote:Have you centred the shoes?
Only by eye. Is there a technique?
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 12:26
by bigherb
Winchweight wrote:bigherb wrote:Have you centred the shoes?
Only by eye. Is there a technique?
First just make sure the wheel cylinders are not seized.
The adjusting pawl should be slackened right off on the crossbar.
Offer the drum up then check there should be near equal distance top and bottom of the shoes. Slide the shoes up or down to adjust.
Then half fit the drum making sure it is centred over the splines or studs, then adjust the shoes making sure you have equal distance at the top and bottom of the shoes as you go.
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 13:03
by what2do
Winchweight wrote:Thanks guys. The new shoes areTRW and I have new cylinders I could fit. I already tried removing the reservoir cap and squeezing but it made no difference.
When you say it made no difference, do you mean the Pistons went all the way in or they just didn't move?
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 13:51
by Winchweight
what2do wrote:Winchweight wrote:Thanks guys. The new shoes areTRW and I have new cylinders I could fit. I already tried removing the reservoir cap and squeezing but it made no difference.
When you say it made no difference, do you mean the Pistons went all the way in or they just didn't move?
They move freely back and forth and when squeezed they feel like they are both fully retracted.
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 16:00
by Mr Bean
I may be teaching Granny to suck eggs but:
I suppose you have removed the thin ridge of rust and unworn area round the rim of the drum. Sounds OTT but I use an electric power/finger file on the unworn area when I do mine. I center and align the shoes by hooking the drum on the edge of the shoes to one side and tapping with a mallet to gather them into position.
CS
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 16:50
by Winchweight
Yup, lip removed (there wasn't much anyway). I'll try again and try to be more patient.
Re: Brake drums won't go back on.......
Posted: 19 Jul 2017, 17:08
by scaltura
Brake adjuster may be 180 degree out, at the end that has different length, I.e so it activates handbrake.