Front brake cylinders

Post by **chrisw** » Sun May 01, 2005 9:59 pm

Help! Trying to change front slave cylinders and flex pipes, 69 Traveller.. A plea for advice as you guys must have met these problems before.....
1. Despite soaking all day in WD40, flex pipe nut at inboard end impossible to shift and bracket cannot take many more attempts. Yes, I am using the two spanners approach! Any tips?

2.Can someone advise spanner sizes for retaining bolts please, particularly the smaller one? Previous owner(s) seem to have mangled the heads pretty well and I can't get anything to fit. How do I shift the blighters?

3. If I have to resort to removing backplate, how easy is it to get the hub off? I do not have a puller. Tech manual suggests two large levers - as easy as that or will I run into problems with bearings etc?

Post by **bmcecosse** » Sun May 01, 2005 10:53 pm

Hub comes off very easily - if needs be - two tyre levers on the wheel cylinders will pop it off. Remember LH nut on the passenger side ! You will need to destroy the flexi pipe (and maybe also the bundy pipe) - then apply heat and large ring spanner. If the flexi is in good shape you can just take the backplate off - and twist it off the flexi - provided you can get it loosened at that end !! Have something handy to block it with to prevent all the fluid dribbling out. Sorry don't know the bolt sizes for the cylinder - much easier if you can bench it to see what you are doing ! While in there - check your bottom trunnions - mine literally fell off in my hand on Friday when i was working on the brakes !! And there had been no warning - no clunks - not stiff - no obvious 'play' - and very regularly greased. Better it happens in the driveway than on some dark and wet backroad !!

Post by **Alec** » Mon May 02, 2005 7:39 am

Hello Chris,
Wd40 is not the best release fluid, Plusgas is considered better, however in such a case i would cut off the nut. I suspect you will also need to replace the metal barke pipe also unless it is a copper\brass pipe and union.

The bolts could well be Whitworth which will explain the mangled heads. I would get new bolts and use mole grips to remove the old ones unless you can drive a socket onto them.

And yes, as stated above, the hub comes off easily, very often just by pulling with your hands.

Alec

Post by **57traveller** » Mon May 02, 2005 12:29 pm

Re front slave cyl. securing bolts - the short bolt is 5/16"UNF, 1/2"A/F spanner.
The longer bolt is 1/4"UNF, 7/16A/F spanner.
As for the flexi pipe - the connection to the cyl. needs a 5/16"Whit spanner, the other end of the pipe is 3/8"Whit spanner and the larger securing nut is either 1/2" or 9/16"Whit spanner. (1/2" I think)

Post by **bmcecosse** » Mon May 02, 2005 1:05 pm

You sure 57 ? I think they are smaller than that - maybe 7/16af and 3/8af .

Post by **bigginger** » Mon May 02, 2005 1:28 pm

They appear (whether by replacement or design) to vary. Having just been playing with brakes from 3 different Minors, I'll vouch for that - and just how awkward they can be...
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Post by **57traveller** » Mon May 02, 2005 2:16 pm

bmcecosse wrote:You sure 57 ? I think they are smaller than that - maybe 7/16af and 3/8af .

100% sure for the Lockheed cylinder that I checked and just rechecked! So maybe there is a variation. 7/16AF spanner is correct for the 1/4UNF bolt and 1/2AF spanner is similar for the 5/16UNF bolt.
Also seen them fitted using socket head bolts.
Plus, the holes in the backplate (8") also correspond exactly to 1/4" and 5/16" bolt sizes.

Post by **bmcecosse** » Mon May 02, 2005 9:33 pm

I was maybe thinking of the similar Mini arrangement - which has smaller screws.
Anyway - what's the progress chrisw ??

Post by **57traveller** » Tue May 03, 2005 8:56 am

If anyone does encounter socket head bolt(s) then a 3/16" Allen key is required for the 1/4" UNF which is the usual to have a socket head because there isn't much space between a hex. head and the cylinder body if using a ring spanner or socket.

Post by **chrisw** » Tue May 03, 2005 1:40 pm

Thanks very much for all the info, guys. Progress has been a bit spasmodic due to seized nuts (on the car that is!), shopping for Plus Gas and other items on the domestic agenda. Hub is off as suggested , backplate on bench, cleaned of crud and semi-stripped at time of writing. Larger bolts out OK with 1/2" AF but smaller ones are weirdo's. Must have beeen last put in by someone with a sense of humour. One surrendered to 8mm ring spanner from the Eurobox's toolkit, t'other is very badly rounded,rusted and resisting but will be assaulted in next session! While beavering away I wondered what the old BMC scheduled workshop time would have been for "change front slave cylinders". Anyone got a copy of such schedules? Would make interesting reading.

Post by **bmcecosse** » Tue May 03, 2005 10:39 pm

There's usually stuff like that on ebay.

Post by **57traveller** » Wed May 04, 2005 3:57 pm

I've got a copy of BMC dealer repair/replacement prices for 1957. Unfortunately only just noticed the section on brakes is missing. It does look as though prices were fixed for the job. However, the "small print" is also missing so possibly unforeseen circumstances may have been covered by that.

Morris Minor Owners Club