Brake system re-build

Post by **salty_monk** » Tue May 11, 2004 6:21 pm

I have a couple of weeping cyclinders, rusty looking inner chassis leg wher old carpet has dropped down & held water around the master cylinder & some half worn out shoes, one of which must be contaminated to some degree (it's leaked all the oil out over the course of six months - the system then took a big gulp of air & become ultra spogey thus alerting me to the problem!

As I going to have to do these 2 cylinders & change the shoes (and in my experience it just moves around the system, the next weakest cylinder goes & contaminates the new shoes & so on until finally you end up with the master cyclinder going) I thought I may as well go the whole hog & do the lot now in one hit, change the master cylinder as well as all the cylinders & shoes, have ordered the bits & basically a full set of brake pipes come free...

2 questions:

a: is there anything I need to watch out for that you lot want to tell me about?

b: is it worth re-running all the brake pipes? This car looks to have had loads of work done on it in the past & the brake pipes all look as if they have been replaced with copper ones at some stage & the flexi hoses also appear quite new.

oh, one more question... Is it a good idea to be spraying all the bolts (car's already on axle stands) with WD40 for a couple of days beforehand?

One last thing (really this time!), I have a rubber gaitor gone on the offside front kingpin (the one at the top at the bottom of the thread about 3" down the leg) was hoping I can take off the castle nut & the pull the bolt out & then simply unwind the top, slip the rubber over & screw it back on & replace bolt. Am I living in a dream world??

Cheers,

Dan

P.s. Ray - hope you're right about the work easing off after the first year, I'm beginning to wish I'd spent 4 times as much money on one to start with.... mind you I guess it'll be a good source of spares for the next one if & when it finally does fall apart!! (that's if I can't get Steve to swap me his pick-up first; go on, you know you want to!!)

Post by **rayofleamington** » Tue May 11, 2004 7:25 pm

If you are changing all the wheel cylinders and the M/C...
You can convert to silicon brake fluid. It's more expensive and slightly more difficult to bleed but it doesn't suck in humidity and cause corrosion so the brake cylinders should then last a huge amout longer.

Post by **salty_monk** » Tue May 11, 2004 8:04 pm

know any cheap sources or shall I just get Bull Motif to add it on to the rest at £17.50 +vat... (aagh, at that price, what if it leaks!!)

Post by **brixtonmorris** » Tue May 11, 2004 10:32 pm

the split rubber on king pin.
to take the top link off the lower swinging arm has to be split and torsion removed.
then the link can be removed from shock pin. these top link pins are quite difficult to remove from the shock, so best leave it there. You cant support the torsion and try to remove top link, it wont go. so its remove kip pin to remove trunion from king pin to remove small rubber ring. can you get some good rubber glue and try and stick it together.

check that you have a good fit scoket for small bolt on front clyinders. take care with this bolt.
try to use scokets and ring spanners as much as possible
fit lockhead brake clys in yellow box

Post by **Kevin** » Wed May 12, 2004 12:55 am

oh, one more question... Is it a good idea to be spraying all the bolts (car's already on axle stands) with WD40 for a couple of days beforehand?

Why Dan WD40 is not a penetrating oil inspite of its many uses,
If you wish to put anything on it to help unseize things then use Plus Gas.

Post by **Scott** » Wed May 12, 2004 4:52 am

[quote="salty_monk"]One last thing (really this time!), I have a rubber gaitor gone on the offside front kingpin (the one at the top at the bottom of the thread about 3" down the leg) was hoping I can take off the castle nut & the pull the bolt out & then simply unwind the top, slip the rubber over & screw it back on & replace bolt. Am I living in a dream world??/quote]
It is possible to remove the upper trunnion without dismantling the lower arms. Raise the car & put a stand under the lower arms & then lower the car so that the weight of the car is on the arms. The damper arm should be clear of the lower bump stop now. If it is clear of the lower bump stop, the damper arm isn't supporting any weight.
Remove the rear nut (not the castle nut) by releasing the lock tab first. Remove the washers & rearmost rubber bush. You'll find it's possible to move the suspension "upright" backwards slightly & at the same time, twist the upper trunnion off the damper pivot.
I'll admit it it easier with the lower arms split, but I've removed upper trunnions before this way quite easily.

It's easy to remove the castle nut, but the damper pivot pin is on a taper & is very difficult to release this taper while the damper's on the car.

Post by **Kevin** » Wed May 12, 2004 8:46 am

but the damper pivot pin is on a taper & is very difficult to release this taper while the damper's on the car.

It can also be difficult/impossible to remove with the damper off the car, my local specialist has a fly press and if it does not shift with a couple of goes they leave it in place for the reconditioners to remove, as they say customers would get a bit upset if they spent half an hour removing the pivot pin when a new one is only a couple of quid.

Post by **salty_monk** » Wed May 12, 2004 9:02 am

What do you guys think of this comment:

DOT5 fluid does not absorb water. This means the boiling point will remain relatively stable, but it also means that any water that does get into your brake system will tend to form pure water pockets, which could cause brake corrosion.

On here http://auto.howstuffworks.com/question451.htm

If the fluid doesn't absorb water.... how would it get there in the first place??!

Post by **Kevin** » Wed May 12, 2004 2:06 pm

If the fluid doesn't absorb water.... how would it get there in the first place??!

Beyond me we need Colin the Chemist to answer that I think.

Post by **Matt** » Wed May 12, 2004 3:37 pm

Surely small amounts would get in from the atmosphere when you check fluid levels etc.....

Post by **Kevin** » Wed May 12, 2004 3:43 pm

No just keep the doors shut when checking the level

Post by **57traveller** » Wed May 12, 2004 5:10 pm

Have a look at http://www.automec.co.uk/press.html

Post by **Matt** » Wed May 12, 2004 5:10 pm

theres still water in the atmosphere!!!!! theres never 0% humidity (definately not in the UK!!!)

Post by **57traveller** » Wed May 12, 2004 5:22 pm

Conventional fluid absorbs/attracts moisture, silicone does just the opposite. So other than pouring water into the system it will not get in. I suppose minute amounts from the atmosphere may end up in the filler neck or above the fluid in the MC when checking level but surely that's all. Any that enters parts of the system opened for maintenance will be purged out with the air and lost fluid.

Post by **salty_monk** » Wed May 12, 2004 5:41 pm

Have a look at http://www.automec.co.uk/press.html

Interesting... so it depends on who you believe I guess!!

Post by **brixtonmorris** » Wed May 12, 2004 6:20 pm

shall i make a post about how to remove a taper fit. theres a secret.
does anyone know it?

Post by **Theo** » Wed May 12, 2004 8:22 pm

tell us

Post by **salty_monk** » Thu May 13, 2004 2:06 pm

Why Dan WD40 is not a penetrating oil inspite of its many uses,

Lucky I don't have any then... It'll be GT85 I think!!

Post by **salty_monk** » Sat May 15, 2004 6:36 pm

Looking at the master cylinder today, the bolts are trapped by the torsion? bar that runs along side the chassis.
I guess I have 2 ideas here & wanted to find out which are tried & tested...
1. Release the bar at the rear end from the chassis & try to lever it enough to get the bolts in & out.
2. Cut the heads off the bolts, pull them out backwards & then re-install with the bolt heads on the inside of the chassis beam on re-fit.

What do we reckon??

Post by **Kevin** » Sun May 16, 2004 9:19 am

Salty if you look in the technical tips section its all explained there including reversing the bolts and what can go wrong on rare occasions.
http://www.morrisminoroc.co.uk/technica ... moval.html

Morris Minor Owners Club

Brake system re-build

Brake system re-build

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