brake probs?

Post by **Tim_nz** » Sat Jan 31, 2004 3:21 am

hey all

in my 1959 morris minor 1000, the brakes seem to be dead.

the pedal goes straight to the floor without any pressure what so ever, and even when you pump them, theere is no difference.

anyone had this problem??

Post by **brixtonmorris** » Sat Jan 31, 2004 9:48 am

check the level of fluid in the masterclyinder under your feet. if its empty youve got a leak. if its full, your master clyinder has failed.
you can use a the spark plug spanner to undo the master clyinder fill nut.
this also could be a air lock, but this only applies if work has just taken place on the brakes.

Post by **Tim_nz** » Sun Feb 01, 2004 5:42 am

yeah where is the fill nut? is it just under the carb?
we checked that the other day, not much fluid in there!

Post by **Kevin** » Sun Feb 01, 2004 10:06 am

No the master cylinder is under the drivers side carpet.
The one on the top of the carb is the dashpot and should only be filled to the shoulder that you can see and not to the top.

Post by **salty_monk** » Tue Feb 03, 2004 10:59 am

And don't fill it with brake fluid either if it's the dashpot... use engine oil, anywhere between 10w & 20w should do it although:

yeah where is the fill nut? is it just under the carb?

The only thing I can think of under the carb is the float chamber (I think that's what you'd call it) & this will have petrol in it not oil & will be connected directly to the electric fuel pump by a flexible fuel pipe from memory...

If you are looking at the master cylinder make sure you check what type of fluid is in the system; you can't mix mineral with Silicon as it'll make them fail (again...) you should be able to smell which it is.....

Post by **rayofleamington** » Tue Feb 03, 2004 11:09 am

you can't mix mineral with Silicon

and the minor brakes don't use either of these fluids anyway....

Post by **Cam** » Tue Feb 03, 2004 11:51 am

you can't mix mineral with Silicon

Ha Ha! I'll let you tell our local branch secretary that!!! he has both in his system!! - it works but for how long????

Not recommended!!

Post by **57traveller** » Tue Feb 03, 2004 12:14 pm

Had silicon DOT5 brake fluid in my saloon for over 4 years - no problems whatsoever. Traveller for 2 years similar result.

Post by **rayofleamington** » Tue Feb 03, 2004 12:50 pm

Had silicon DOT5 brake fluid in my saloon for over 4 years - no problems whatsoever. Traveller for 2 years similar result.

The seals are compatable 'in theory'. In practice old seals absorb elements from the various types of fluids used over the years, and also they are affected by age and temperature.
The combination of old seals and silicon fluid is very hit and miss. I know of one example of a complete brake failure and another of swollen/leaking seals caused by silicon fluid used in old cars

Of course the problems occur less often than the positive result, and a lot of people have conveted, but the safest thing to do is to replace all the seals when converting a car.
Cam:
Anyone who gets some mineral fluid in their brakes is not someone I would accept a lift from!!!

Post by **salty_monk** » Tue Feb 03, 2004 2:48 pm

What's the norm in a minor?? Bull motif reccomended ordinary non synthetic Dot 3 or 4....

What do use use Ray? Lockheed special stuff or what??

Post by **rayofleamington** » Tue Feb 03, 2004 3:08 pm

I'm not sure how special Lockheed Dot4 stuff is (my company used to be part of AP....). There's also special stuff around like TLX which is like Dot4 but with some friction reducing agents, but not needed unless you have hydraulic pumps to worry about.

Bull Motif are pretty sensible people and know their Minors.
The advantage of Silicon is that it won't attract moisture and cause corrosion in the same way that Brake fluid does, however if you regularly change your Brake fluid and keep an eye on your cylinders you'll generally be fine.
Silicon does have some disadvantages such as it can be more difficult to remove air from the system and also the unknown factor on old seals, but once you're up and running you should be better off.

I just use Dot4 (from anywhere that is open - sometimes Halfords if it's a Sunday afternoon ;-)), but I don't get through very much of it at all. I changed my master cylinder a year ago (mid winter) and didn't need to bleed the car. The brakes are sharp with almost no pedal travel so I put off bleeding the brakes until it was warmer...
It's amazing how life gets in the way of the back burner jobs

Post by **salty_monk** » Tue Feb 03, 2004 3:10 pm

Like dropping off seat belts.... I could have done it tonight but I forgot to bring them up with me... Next week!

Post by **rayofleamington** » Tue Feb 03, 2004 3:13 pm

salty_monk,
That's fine - I am off to Gatwick at 4:30 am so a few less thigs to do this evening is fin by me.

Post by **57traveller** » Tue Feb 03, 2004 4:30 pm

If I'm not mistaken, isn't mineral based fluid only used in two or three specific makes of car? - Citroen, Rolls Royce to name a couple.

Ray - forgot to mention in my earlier post that the complete braking system was renewed in both cars prior to using the silicon fluid

wheel cylinders, master cylinder, flexible pipes etc.

Post by **rayofleamington** » Tue Feb 03, 2004 4:46 pm

Ray - forgot to mention in my earlier post that the complete braking system was renewed in both cars prior to using the silicon fluid wheel cylinders, master cylinder, flexible pipes etc.

Ah well, then maybe you already heard about the problems of Silicon fluid... (Or maybe you are just thorough?)

Post by **57traveller** » Wed Feb 04, 2004 9:14 am

Sorry, posted in error.

Post by **57traveller** » Wed Feb 04, 2004 9:17 am

57traveller wrote:Had silicon DOT5 brake fluid in my saloon for over 4 years - no problems whatsoever. Traveller for 2 years similar result.

Just thorough

However, I suspect that the small minority who have experienced problems have not read the instructions properly or are using SBF as a scapegoat/excuse for existing deficiencies in their braking system.

Post by **rayofleamington** » Wed Feb 04, 2004 8:16 pm

Actually my former boss (Paul) had the swollen seals in his Vitesse. It was an aquaintance of Pauls' that had the total brake failure in a Riley a year after Paul's problems.
My boss had worked for AP (brakes and clutch hydraulics) for the last 20+ years. Having worked in Automotive hydraulics myself for more than 5 minutes it's immediately apparent about compatability problems.
Although as Paul's a Vitesse owner he's probably a cowboy...

Each seal material has to be tested for a specific application and it's amazing how seals that are 'brake fluid compatible' can give totally different results when used in Dot 3 or Dot4 or TLX (like Dot4 but with friction reducer agent).
Elastomeric seals will absorb elements from the hydraulic fluid - and they also loose elements into the fluid. I would expect that there is some 'bad combination' of seal + brake fuid type finished off by silicon fluid.
New seals shouldn't have that problem, so hats off to anyone who's good and thorough!

Post by **iwant1** » Mon Feb 09, 2004 9:03 pm

i dont think i have a brake problem as such, only i dont know how good they should be theres loads and loads of pressure on the pedal, and i rebuilt the master cylinder, and inspected the drums all round. The car stops, but not with and expected jolt if the pedal is forced vigorously. The car was stood up for a while though, anyone heard of the brake shoes being glazed or too shiny to be good, and can this be removed merely by holding the brakes slightly on and driving for a bit?? thanks all. Ben

Post by **Scott** » Tue Feb 10, 2004 4:56 am

It's possible you might have a couple of seized wheel cylinders. Did you check these while the drums were off?