thanks
[Edited on 22/11/11 by Mr Whippy]
Hi,
I'm having issues with the Landys brakes and am not sure what exactly it is that's wrong with it since I've never seen this fault
before.
I replaced all the drum brakes all round (series III) slave cylinders and all and then bled it with a Easy Bleed till no air came out. Problem is when
I press the brake pedal it sinks way down with little brake power, then lift it and press down again and the pedal is hard and the brakes work fine!
Before using a friends Easy Bleed I had no luck removing the air and fizzing in the brake reservoir, I was wondering were the hell all this air is
coming from.
Any ideas? looks like I will have to replace the master cylinder just to be on the safe side.
Thanks
sounds like it needs bleeding again. but we will soon see......
Have you adjusted the drums if there is to much movement it may fill like that
[Edited on 22/11/11 by doddy]
I have heard of similar problems, solved by jamming the pedal down overnight. Actually that was on a clutch, but maybe worth a try?
You've got the same size slave cylinders as before I take it - If you've increased the size there may not be enough fluid moving in one
stroke of the master cylinder to fill the slave cylinders correctly.
Regards
Hugh
With drum adjustment, on each backplate you have a 1/2" square peg that you turns the snail adjuster inside, turn until it binds then back one
notch.
Failing that master cylinder seals could be shot and only hold fluid when under pressure.
Regards Mark
no air in the system that's for sure, I did it twice and not even the smallest bubble came out.
I took up all the play in the shoes with the adjusters till they were just starting to drag on the drums. Though I will double check when I get
home.
If I press it down twice the pedal stays there with full brakes, no sinking as you expect if air in the system was cooling down. If I then press the
pedal a couple of seconds later the pedal is still fine, but if I leave it for say 10 seconds and press it is all soft again!
From that last description I'd be looking at the master cylinder seals as suggested above.
Hugh
quote:
Originally posted by Mr Whippy
no air in the system that's for sure, I did it twice and not even the smallest bubble came out.
I took up all the play in the shoes with the adjusters till they were just starting to drag on the drums. Though I will double check when I get home.
If I press it down twice the pedal stays there with full brakes, no sinking as you expect if air in the system was cooling down. If I then press the pedal a couple of seconds later the pedal is still fine, but if I leave it for say 10 seconds and press it is all soft again!
another vote for the master cylinder from me, i had the same problem with an old golf cab i was restoring a few years ago, new master cylinder cured it.
sounds like it is the master cylinder then, all the brakes are bog standard and I have not uprated anything. I'll be glad to get it sorted as the
brakes may be simple on it but have heaps of pipework that needed replaced, bit miffed that it is still playing up after all the work I put into it
thanks
[Edited on 22/11/11 by Mr Whippy]
Clamp all the flexies then try it again, if the pedal is good, the MC if fine.
Next step is to check the manual adjustment on the drums, if this is fine, you have a leak in the system somewhere.
If there is no leak, one of the flexies may be ballooning - bit of a longshot
If none of the above - its probably haunted
Mark has posted some good commonsense advice just to add a couple of extra points
You can't bleed a system fully with an Eezybleed to get air out the master cylinder the pedal needs to be pumped a couple times for each
circuit to get air trapped in the master cylinder out, you can do this with the Eezybleed on.
Most likely cause is the master cylinder problem or leak at a union.
A new seal kit in the master cylinder should fix the problem
Trick of the trade that saves a lot of time: ==== After rebuilding the cylinder hold it in the vice with bleed nipples in the outlets, fill it
and bleed it through to prime it.
The top it up with fluid brimmed to the very top and stretch some cling film over and secure it air tight with an elastic band --- if there is
no warning switch in the cap then screw the cap on.
Then refit the cylinder, remove the cling film and bleed through.
Hmm.. Seen this before.
Also as a test, adjust all the brakes up hard until the wheels lock, then test the pedal.
The snail cam adjusters are OK when new, and crap when old and worn like yours probably are.
These are relatively cheap parts to replace (you can get a kit).
Also check the holes in the back plates for the adjusters arent oval.
Sounds like possibly a bit too much play in the system.
good luck.. Series brakes can be fun!
Try paddockspares for bits, and brakeparts.co.uk for the shoes.
Also keep an eye out on the oil seal in the transmission brake as these tend to leak into the drum. not often notices until the MoT man see it.
I've just helped with a IIA onto a galvanised chassis and it had the same thing. It was just air in the brakes and they needed bleeding again. They were done the old fashioned way furthest from the cylinder first working towards it and they are fine now.
When I rebuilt my S2 - It had sat parked up for years, changed all the pipes & wheel cylinders/shoes and crossed my fingers with the master
cylinder.
Had exactly the same issues your having.
I put it down to me disturbing the master cylinder seals with the system all drained down, once renewed the pedal came back.
Used to have this an awful lot on some vauxhall fleet vans i worked on ...
The master cylinder seals 'relax' when you open the system to change the wheel cylinders. The flared seals 'flare' when you pump
the system pressure up with the foot pedal but relax again when you leave it for a while.
New master cylinder seals solved the problem.
...as has been suggested above.
Worth bleeding the guts out of it again though .... brake systems are the work of the devil and can hide air.
great
thanks guys, plenty to look at when I get home
Master cylinders build up a lot rust, & rubber crap inside after a few years use, once you bleed by pumping the pedal you disturb it it gets under the seals potential problems result.
Had a similar thing on a customers 2cv some time ago, had us in a tizzy for a while until we noticed the pistons in the slaves were retracting on their own leaving a gap between piston and shoe, overzealous dust covers on our case, may be worth a look
Had same prop years ago with landrover.found that i had put shoe return spring to wrong hole and that was upsetting it .pedal was very sponge like or felt like out of adjustment
I've had (and have) many flavours of Leafers.
IF your SIII is a 109 (as my SII is), or has had some history, you'll have the twin leading shoe fronts. You'll notice (if so) that the
flexi pipe goes into the top cylinder, with the bleed nipple on the bottom cylinder. It REALLY IS DIFFICULT in this case to get a good pedal. One
resort is to remove the backplate, rotate through 180 degrees, bleed away, and replace.
IF you have the huge compression barrel cast-iron master cylinder fitted (with the big nut on the back) - make sure you fit a compression barrel type,
not the 'normal' looking one. If you replace it with such a type, you'll get EXACTLY what you describe here.
IF you've fitted the rear shoes the wrong way round - YES! - it's very easy and very common. You'll get exactly what you describe here.
I haven‘t read all the posts here but i thought i would tell you about two similr problems related on another forum.....both people had replaced master cylinders as well as rebuilding the full brake system including new caliper seals......the problem for both was that the calipers were fitted to the wrong side thus the bleed nipples were upside down! one lad had spent a fortune on brake fluid (over a gallon) and was almostat the point of giving up his project.....swaping the calipers solved both problems.
quote:
Originally posted by snowy2
I haven‘t read all the posts here but i thought i would tell you about two similr problems related on another forum.....both people had replaced master cylinders as well as rebuilding the full brake system including new caliper seals......the problem for both was that the calipers were fitted to the wrong side thus the bleed nipples were upside down! one lad had spent a fortune on brake fluid (over a gallon) and was almostat the point of giving up his project.....swaping the calipers solved both problems.