Brake Question

[SeriesCanuck]

I just introduced myself here yesterday and already I have a question.

I just recently got my IIA 88" home and when it came off the trailer the brakes were working fine.

They worked fine for the previous owner who drove it daily. I have had it sitting for a couple days in the driveway and when I started it up last night (it was -37 deg celcius...can you beleive it started?) I noticed that the brake pedal went straight to the floor. Pumping did not help.....ie no brake pedal pressure at all.

I immediately checked to see if any fluid was under the truck (nice white snow should reveal something)....but no fluid noticable.

Since it was very cold...I haven`t gone over it that carefully yet.....but when I do....what should I be looking for

[jp-]

The most likely thing that happened is that the truck has been leaking fluid slowly for a while, and the owner didn't catch it. It finally reached a point low enough that air was drawn into the system when the pedal went to the floor. The other less likely possibility is that a seal has blown and you lost all the fluid at once. If that were the case, there would have been a nice big puddle either on the inside floor or running down the outside of the bulkhead.

In either case, at the very least, you will have to find the leak (at the master cylinder or wheel cylinders) and replace the leaking components (possibly all the components based on the condition that you find them in) then bleed the entire system.

What shape are the brake lines themselves in? Flex hoses?

[S11A]

I agree with JP - it is likely a leak. The way hydraulics work (sorry if this is too basic) is that the brake pedal forces fluid in the master cylinder through the brake lines which then forces the wheel cylinders to force the shoes/pads against the drum/disc. Fluid is incompressible, so if the pedal goes to the floor, then the fluid can't be there (or there is a LOT of air in the system).

I had the brake fluid changed at a dealer once (different car) and the idiots left the fluid reservoir cap off. Worked fine all the way home and for another few days, until I popped the hood for something unrelated and saw the cap sitting there. I about fainted at thoughts of what could have happened. Funny things was - not much fluid had splashed out.

Anyway, check the reservoir and see if it looks low. If so, add fluid and then bleed. Look for leaks - bleeding might force the fluid out of the leak(s) and make it more apparent where the leak is.

Look at the rubber hoses going to the wheel cylinders as a first stop. Check all components in the system, even if find one leak - there could be more leaks or the other components could use replacing or repair too.

[greenmeanie]

Sorry for the thread hijack but this brings up a question I have about my new daily driver/family truck which is somewhere up in Colorado right now.

How many people here have the single circuit brakes and how many have seen fit to convert to dual circuit. My new truck is a 67 109 SW so, unless reworked previously, it should be single circuit. The safety concious part of me says I should convert over to dual circuit but I just wanted to get an idea of what others have experienced to see if it is worth the hassle. The pedal tower seems to be about he worst thing to get hold of although I think it can be done with 110 parts.

As usual I understand that a properly inspected and maintained system is a safe system. Just wondering if anyone has had any OH SH!T moments or anything.

I would rather spec out and overhaul/rework the entire system at once rather than find out the hard way.

Cheers
Gregor

[jp-]

I have not coverted my 109". The brake pedal is a little hard to push, but seems to stop fine. I didn't want to chop my fender up. The servo has also been removed. Takes a little bit of "leg" power to stop quickly.

No "oh ****" moments yet, but after coming out of deep water there is absolutely no pedal until the shoes dry, no matter how hard you push down.

[O'Brien]

well i almost rearended an S500 mercedes this morning because they slammed on their brakes about three car lengths ahead of me to make an unprotected left turn. thank goodness no one was parked on the curb!

upgrading to a dual circuit is on my to-do list. eventually would love to do a disc conversion as well.

at some point in a past life someone already cut my fender (really nice clean job though). so i'll just pop out a few rivets and go to town. but yeah the singles on the 109's a kinda tough to get a good pedal on unless the whole system is perfect. (either that or im an idiot)

[greenmeanie]

Well she's still sitting around up in Colorado so I won't know what I've got until I see it. Having said that the owner referred to a large donut shaped thing when asked so she may have a servo on there already. Am I right in thinking there was a version that had single circuit with a servo? The name Clayton Dewandre or something like that springs to mind.

As far as problems I'm thinking more of the foot suddenly feeling wet and trying to get some, or any brakes feeling because of a leak in the system.

Oh, and to get back on track with the original thread I would first check the fluid reservoir. As someone said earlier it will all be good until that very last pump that uses the last of the fluid and then allows air into the lines. After that a I would get some PB Blaster on the bleed nipples for a day or so and then bleed the system furthest to nearest cylinder order. With that and a top up you might find you are good again.

Also look at the inside of your tyres. If there has been a wheel cylinder leak it can show up as radial lines on your tyre.

Cheers
Gregor

[SeriesCanuck]

Thanks for the replies.

I just went and checked a little more at lunch. The resevoir was low. I topped it up but it didn't make any difference. Will try to bleed them.

One thing I noticed was that the res cap doesn't get tight. As I screw it on, I can just keep turning ....feels like it gets to a point that it might tighten then just becomes loose again.

This probably isn't normal. Could I assume with the cap not tightening that I would be loosing fluid (it looks like it could have been at the resevoir) and drawing air into the system?

I can't see any other physical evidence at the wheels or line yet.

[SeriesCanuck]

oh yeah...btw....flex hoses and seems to be a single circuit..are they shared (brake and clutch)?

[S11A]

Doubtful that a loose cap would cause an issue - see my previous comments about not much fulid being lost without a cap at all. (That was street driving, offroad, gravel, or really bad road would probably be worse.) In any event, as long as the cap was on, not much would probably make it past the threads.

Not sure about Land-Rover reservoirs, but most feed from the bottom, so you would have to be almost out of fluid before it started sucking air?

[jp-]

Thanks for the replies.

I just went and checked a little more at lunch. The resevoir was low.

Need more info.

On the IIA, the res serves both the clutch and brake. The middle of the can holds the clutch reserve and the outside holds the brake reserve. Was it the middle that you were referring to as being low? Because the outer res would need to be almost empty before pulling air into the brake system. Often its hard to tell which is low without a flashlight.

The only thing I am trying to point out is that the system should not have lost pedal pressure unless the fluid ran almost completely out of the outer ring.

[LaneRover]

Once when I was driving my 65 109Sw in LA I went to turn and my brake pedal went straight to the floor, no warning no hints nothing. One pump and the same and then after that it was like nothing wrong had happened and it never happened again. (Then a few months later went with dual circuit brakes)

I guess I am saying that strange unexplained things happen on occasion with my trucks at least. You did mention that it was -37 degrees the night before and that can freeze up and thus destroy some rubber seals that may have been a bit iffy but not shown it previously. It could also shrink a seal so that it doesn't seal.

If you are pumping with no pressure but you don't have to constantly add fluid I think that would point to a problem with a seal somewhere. Try clamping off the various wheel cylinders to narrow everything it down.

Did the clutch work?

Brent

[Jeff Aronson]

If you have fluid in the reservoir, and it never went dry on you, then you most likely have a master cylinder failure. If you had a line fail, which can happen, then you would have lost some fluid, too.

If you have no fluid dripping down the brake pedal, inside the car, then the failure can be of the seals inside the cylinder itself.

The failure can be quite sudden; it happened to me on my single circuit II-A while trying to bleed the system. I chose to install a new cylinder myself. The job was tedious but not that difficult to accomplish successfully.

There are enthusiasts who swear by rebuilding the master with a simple kit. If the insides are not pitted, it is supposed to be relatively easy. With brakes, I like them to work reliably so I went with a new master cylinder instead.

This is all fixable, even in winter weather. I know because I've done it myself, outdoors, and I am fairly inept :)

Jeff

[SeriesCanuck]

hmmmm.....I didn't realize there was an inner and outer on the resevoir. If that's the case, I didn't see any fluid in the outer ring. I will check on it and inspect for any leaks.

[S11A]

If you have fluid in the reservoir, and it never went dry on you, then you most likely have a master cylinder failure. If you had a line fail, which can happen, then you would have lost some fluid, too.

If you have no fluid dripping down the brake pedal, inside the car, then the failure can be of the seals inside the cylinder itself.


Good points. The fluid could be simply squirting past the seals instead of being forced through the lines.

Another option, however, is that there is a lot of air in the system. IIRC, he just got the car, so we don't know what the former owner did to it. The former owner may have topped up the fluid w/o bleeding, and figured that would do 'er until the new owner got the car off his property. And left a lot of air in the lines. That theory might not explain the fact that the brakes seemed to work OK for a while, however. Jeff's broken seal might exaplain that better.

Bleeding would narrow down the possible causes.

[S11A]

On a related topic, has anyone used Speedbleeders on a Series? I have them on my autox/track car and love them. So does my wife :-) I can't see why they would not be a good option, but experience is always appreciated.

Actually, I am installing the Defender disc brake kit from our hosts, so I guess the question would apply to those...