'73 Series III rear brakes problem

[1973series3]

After my Rover sits for a couple of days the rear brakes drag pretty heavily.

The shoes are new, the snail adjusters are adjusted all the way to the "loosen" position so they are not over adjusted.

The wheel cylinders do not leak.

And I replaced the rubber line at the rear.

Incidentally,the brake lights stay on like the switch is stuck on.

These could be 2 different problems, but I am not really sure what would be my best move to be to fix this issue.

Hopefully you all can help out. :cool:

[SafeAirOne]

I would look for an obstruction in the plumbing or an improperly adjusted or malfunctioning master cylinder. Also, I'd check that all the rear brake shoe springs are on properly. TeriAnn has a good page (or pages) on brakes on her site. Google "TeriAnn Wakeman land rover" if you aren't familiar with the site.

The brake light switch on the SIII is mechanical and it resides on top of the brake servo tower. Easy to get at and see what's going on with it.

Is your brake pedal retracting fully?

[slowmo]

Not sure about the system on a Series 3, but if the master cylinder doesn't release the pressure when the pedal is released, it seems the brakes would remain locked AND the brake light would remain on. Wild a$$ guess but I think a master cylinder kit or replacement is in order.

Of course this would occur during regular driving as well. If that is not the case...are you sure it is the rear brakes and not the transmission brake? Could be the tranny brake needs some attention?

[TravelinLight]

A common problem is the springs being installed incorrectly. Can you post a picture of how you have them set up?

[1973series3]

The springs are installed correctly, I guess I should have thought to type that in my first post. While I was trying to eliminate the more obvious potential causes.

The pedal is in fact retracting fully. And the park brake is perfectly adjusted and brand new.

I too am wondering about the master cylinder, would it be easier to change the entire unit or buy the rebuild and fool with it?

As far as an obstruction in the line...I had wondered about that too, but surely after bleeding the system several times anything in there is out by now I would think.

[Les Parker]

Unless one or more of the brake hoses is failing internally, causing a flapper valve effect.
When were the hoses last replaced?

[1973series3]

I have no way of knowing that. Other than the rubber line at the rear that I replaced recently.

So, do I replace the master cylinder or start pulling rubber lines?

[LaneRover]

Not sure what would cause it to happen. I had one that built up pressure IF I used the brakes a lot. That was a deteriorating brake line.

Is there anyway that this could happen when the booster lost its vacuum over a few days? Almost like there was a tiny hole of sorts that then caused caused the pressure to build up on the 'apply brakes' side of the booster? Don't know if that is even possible but I can't think of much other than gummy shoes that would get worse over a few days.

[slowmo]

The brake lights staying on still makes me think the master cylinder is not releasing the pressure. I would go that route first. Personally, I would replace the cylinder as kits often don't match up 100% with whatever version you have.

[Les Parker]

So, what was the rear hose like that has been replaced?
Was it leaking, or replaced as a matter of course?

[1973series3]

The brake lights staying on still makes me think the master cylinder is not releasing the pressure. I would go that route first. Personally, I would replace the cylinder as kits often don't match up 100% with whatever version you have.


That is what I was thinking too. But being new to these machines and their quirks, I wasn't sure if I was missing anything else.

I had no idea about the kits not matching up, seems like a new one will be the best next move.

[1973series3]

So, what was the rear hose like that has been replaced?
Was it leaking, or replaced as a matter of course?


I read on here that sometimes due to them breaking down they could possibly cause the issue I am having. I didn't seem to help me.

But I DO enjoy getting RN boxes in the mail.:cool:

[SafeAirOne]

The brake lights staying on still makes me think the master cylinder is not releasing the pressure.

Though I agree that dragging rear brakes is the result of retained pressure in the hydraulic system, I think the brake light is a red herring. Presuming a foreign (to the SIII) pressure-operated brake light switch hasn't been added to the plumbing, the SIII brake light switch is a mechanical switch. If the brake pedal is fully retracting (and the OP says it is), and the switch isn't broken, and the switch is adjusted properly, the light should go out regardless of any pressure retained in the hydraulic system.

[1973series3]

Okay, I replaced all of the rubber hoses with the braided stainless hoses and anew master cylinder from our host, bled the system etc.

Yesterday, after sitting for maybe 2 months, I fired Maggie up and the rear brakes were fine as I started to back up, but after traveling maybe 6ft, the rear braked locked up HARD. When it does this I usually drive forward a little and it sorta works loose, but when I hit my pedal going forward, it really locked up my brakes.

This event seems to culminate after she has sat for an extended time.

I eventually got it out of the garage and went for a drive.

I must confess, this is really getting me down.

[SafeAirOne]

Is the MC rod adjusted IAW/the FACTORY workshop manual?

[printjunky]

100% agree with Mark. Brake light symptom is likely a separate issue.

The most important variable seems to be the "sitting for awhile." Seems unlikely that would be a factor in whether the system retained pressure (other than by coincidence).

I doubt this is related, but it reminds me a bit of a condition I get sometimes, under certain circumstance (especially the "after it's been sitting " thing).

About 10% of the time, after getting wet, then sitting for 24+ hrs, the first time I brake, I get a "catch" in the brakes. Kinda makes a bang/chirp, and provides a moment of resistance, almost like it's going to lock up - but it never gets really close to that. As soon as I release the pedal, it rolls fine (and never feels like it wants to really lock up, even if I kept the pedal applied). No other affect, and usually just happens one time. I always assumed it was a matter of a little flash rust on the drum (and maybe a trailing/leading shoe position - can you flip those?). When it first happened it seemed a bit dramatic. But it is really not, and otherwise the brakes work great.

99% of the time, when it does this, after hitting the brakes (and "catching") once, it's done. It ONLY happens at VERY low speed (I go down a hill from my driveway, so apply brakes pretty quickly). Once in a great while it takes a couple of "catches." The degree of apparent dramatic-ness varies. Most of the time it doesn't happen, of course. When it does, sometimes it's barely a tick, others, it will be 3 stronger, separate "catches," before it's gone (like once on the hill, once (usually lesser) at the first intersection). It's always gone by a couple of brake applications AND if I drive without braking right away (eg: I'm not at home, on the hill), it doesn't do it at all (braking at speed probably clears it without having any noticeable affect due to momentum). Length of time sitting seems to be an important variable. That and the very slow speeds at which I usually brake for the first time.

[ignotus]

It can be that the shoes need some additional chamfering to stop from dragging. It seems to be a new phenomenon I think that crappily made parts are at fault, perhaps not the correct arc on the shoe. Read; http://www.series2club.co.uk/forum/forum/index.php/topic,6606.0.html

[1973series3]

100% agree with Mark. Brake light symptom is likely a separate issue.

The most important variable seems to be the "sitting for awhile." Seems unlikely that would be a factor in whether the system retained pressure (other than by coincidence).

I doubt this is related, but it reminds me a bit of a condition I get sometimes, under certain circumstance (especially the "after it's been sitting " thing).

About 10% of the time, after getting wet, then sitting for 24+ hrs, the first time I brake, I get a "catch" in the brakes. Kinda makes a bang/chirp, and provides a moment of resistance, almost like it's going to lock up - but it never gets really close to that. As soon as I release the pedal, it rolls fine (and never feels like it wants to really lock up, even if I kept the pedal applied). No other affect, and usually just happens one time. I always assumed it was a matter of a little flash rust on the drum (and maybe a trailing/leading shoe position - can you flip those?). When it first happened it seemed a bit dramatic. But it is really not, and otherwise the brakes work great.

99% of the time, when it does this, after hitting the brakes (and "catching") once, it's done. It ONLY happens at VERY low speed (I go down a hill from my driveway, so apply brakes pretty quickly). Once in a great while it takes a couple of "catches." The degree of apparent dramatic-ness varies. Most of the time it doesn't happen, of course. When it does, sometimes it's barely a tick, others, it will be 3 stronger, separate "catches," before it's gone (like once on the hill, once (usually lesser) at the first intersection). It's always gone by a couple of brake applications AND if I drive without braking right away (eg: I'm not at home, on the hill), it doesn't do it at all (braking at speed probably clears it without having any noticeable affect due to momentum). Length of time sitting seems to be an important variable. That and the very slow speeds at which I usually brake for the first time.




To be clear, after sitting and not hitting the brake pedal and backing out of the garage it will travel a few feet and lock up solid on the rear wheels.

I had to put it in 4wd and force it out of the garage the last time. After forcing it to move it finally decided to act normally.

I will add, this never happened EVER until I replaced the shoes.

Hell, I'm about to put the old ones on the rear again(only the rear is creating an issue?) and mail these new ones back to RN so they can check them out.

[1973series3]

It can be that the shoes need some additional chamfering to stop from dragging. It seems to be a new phenomenon I think that crappily made parts are at fault, perhaps not the correct arc on the shoe. Read; http://www.series2club.co.uk/forum/forum/index.php/topic,6606.0.html



I have suspected this but didn't want to taint any replies so I never mentioned it.

[SafeAirOne]

To be clear, after sitting and not hitting the brake pedal and backing out of the garage it will travel a few feet and lock up solid on the rear wheels.
I will add, this never happened EVER until I replaced the shoes.

This clarification could have saved lots of typing, had it come in post #1.

IT'S THE SHOES (or their installation).

[Les Parker]

Mark,, it would be good to know if the rear brakes are set up (spring fitment and drum diameter/condition) the same as the front.


2p

[SafeAirOne]

Mark,, it would be good to know if the rear brakes are set up (spring fitment and drum diameter/condition) the same as the front.


2p

Yeah, I was thinking the same thing when I added "or their installation" to my last post, despite the original poster's earlier assurance that the shoes and springs were set up correctly.

Drum diameter wasn't mentioned by the OP though, and the book has some pretty specific specs on those...


I don't think it's vendor-specific, but I think we've noticed an increasing number of brake shoe-related issues documented on the different Series Rover forums (fora?) over the last 2 or 3 years, many related to friction surface shape/dimensions, IIRC.

[singingcamel]

I would agree with the post, Its the shoes, I'd also turn the drums , check your spring placement as well, easy to mess them up.

[1973series3]

The springs are installed correctly.

I did attempt to put the old shoes on the rear the other day and throw the new ones over the hill, but I have not been able to find the bolts for the old shoes yet.

It figures that they are not the same thread.