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Haynes Roadster - rear upright / caliper / handbrake confusion.
Nickp - 29/12/15 at 12:33 PM

My next job is to try and get my handbrake working so I can move the car up and down my steep drive safely. I thought this would be simple enough but it's proving a bit trickier than anticipated.

The rear uprights that came with the car have the hub mounting flange welded in the straight up and down position, as so-



This means the handbrake cable wants to go through the bottom wishbone mounting lug, as so-



I've read a few posts about a different design for disc brakes with the mounting flange rotated round slightly so that the caliper sits in the 10:30 position rather than 9:00 position (drivers side) to allow the handbrake cable to fit better. I don't want to buy new uprights and would prefer not to chop my existing ones either.
Would it be feasible to swap the uprights from side to side and mount the caliper upside down and in front of the hub? I read somewhere else that MK do this. I know it's not ideal for bleeding but I reckon I could just unbolt the calipers and position them better to do it.

Any other solution?

Thanks in advance,
Nick


Mark100 - 29/12/15 at 01:02 PM

those hubs are for drum brakes the disk ones are the same but the plate is rotated 45% (ish) to avoid this problem cut and reweld maybe ????


Slimy38 - 29/12/15 at 01:07 PM

Swapping calipers seems to be quite a common solution, as you say it's just the bleeding that can be a little fiddlier. But how often will you be doing that?

I'm going to be running my MX5 uprights swapped over, but that's to deal with a suspension issue rather than a caliper issue. But do you have to swap the uprights, can't you just unbolt the mounting bracket from the upright and rotate them 180 degrees? You shouldn't even need to remove the driveshaft if you're careful.


Nickp - 29/12/15 at 01:13 PM

quote:
Originally posted by Slimy38
But do you have to swap the uprights, can't you just unbolt the mounting bracket from the upright and rotate them 180 degrees? You shouldn't even need to remove the driveshaft if you're careful.


Already thought of that to try it, but the top and bottom mounting holes are slightly different distances apart I could probably swap the hubs side to side which would be slightly easier than the full upright.

I'll swap the hubs over and see if I'm happy with the cable and flexi routing before I decide.

[Edited on 29/12/15 by Nickp]


Nickp - 29/12/15 at 01:18 PM

quote:
Originally posted by Mark100
those hubs are for drum brakes the disk ones are the same but the plate is rotated 45% (ish) to avoid this problem cut and reweld maybe ????


Yes that seems to be the case. Seems strange cos it came with the hubs done like this but calipers / discs etc. There does only seem to be one design of upright in the book though so that's probably why.
I'd rather not cut and alter the uprights as they seem really nicely done tbh.


Slimy38 - 29/12/15 at 04:12 PM

quote:
Originally posted by Nickp
Yes that seems to be the case. Seems strange cos it came with the hubs done like this but calipers / discs etc. There does only seem to be one design of upright in the book though so that's probably why.


The book isn't terribly clear, but there are two designs. Fig 5.29 shows the front plate being ninety degrees out for discs and drums. So same pieces, different construction.

And I would agree with not chopping them up, they are very nicely done.


Nickp - 30/12/15 at 05:45 PM

quote:
Originally posted by Slimy38
quote:
Originally posted by Nickp
Yes that seems to be the case. Seems strange cos it came with the hubs done like this but calipers / discs etc. There does only seem to be one design of upright in the book though so that's probably why.


The book isn't terribly clear, but there are two designs. Fig 5.29 shows the front plate being ninety degrees out for discs and drums. So same pieces, different construction.

And I would agree with not chopping them up, they are very nicely done.


Looks like my book is wrong. My uprights are as per the left hand diagram, which says it's for discs but the calipers / handbrake position is all wrong. I've fitted the calipers upside down now and it seems to work well on the handbrake side at least -



[Edited on 30/12/15 by Nickp]


carlknight1982 - 12/1/16 at 08:14 PM

Yes the book is wrong, if you go on the Haynes site there is/was a list of corrections,
I had no end of issues sorting out the disc set up for my car, which was the first Roadster to pass Iva with rear discs,

ill try to find out some photos of the brake set up when I get chance.


Badger_McLetcher - 12/1/16 at 09:25 PM

I've just fitted the calipers upside down mate; when I bled the system I unbolted them and moved them around so the bleed nipple was at the top. Whilst my car isn't on the road, everything seems to work OK


Nickp - 12/1/16 at 09:32 PM

quote:
Originally posted by Badger_McLetcher
I've just fitted the calipers upside down mate; when I bled the system I unbolted them and moved them around so the bleed nipple was at the top. Whilst my car isn't on the road, everything seems to work OK


Good to hear