Brake hose replacement questions

[nick_the_fish]

Next job is to replace the rubber brake hoses with braided ones. Just trying to understand the procedure.

Presumably I need to drain the brake fluid until the system is empty at bleed nipples on each wheel before I can undo the hoses? Is it a case of putting some tubing onto each bleed nipple and letting gravity do the rest? or is there more to it?

Is there anything I need to know about undoing the old brake hose's, or installing the new ones? Do I need some kind of thread sealant or anything.

Then once I have changed out the hoses I need to re-fill the system. What is the best way to do that? I'd like to do it without specialist equipment if possible, so if I ever have a problem while on an expedition we can use the same procedure. I believe you have 2 people, 1 pushing the brake peddle while the bleed nipple is open, and 1 closing the bleed nipple while the brake peddle is lifted. Keep going until the new fluid comes out of the bleed nipple then stop.

Any thoughts anyone?

 

[uHu]

There is no pressure in the hoses when you don't press the pedal, so you can change the hoses without draining the system. If you are fast, you will spill only a few drops, but if you leave it open, it will continue dripping.

When bleeding, the procedure is to close the bleeder before the assistant lets the pedal up. Otherwise it will suck air in. Does the 105 have the same electric brake booster as the 100, or is it like the 80? The electric booster makes it even easier to bleed.

 

[nick_the_fish]

Thanks @uHu

I probably should have mentioned that I need to send the brake hoses away to HEL so they can make the new hoses using the old ones as a template because I don't know if the fittings are the same as the 80 or the 100 (or neither!), so the hoses will be off for a good week or so.

Is it a problem to drain the system? Or I could find something to bung the hoses so the fluid doesn't drain out?

 

[Chris]

Nick. Do NOT bleed the system by pressing the pedal to the floor. On an older vehicle unless you've had a very recent master cylinder change, there is a very real possibility of scruffing up the seals on the piston.

Personally I'd just drain the lot out and start with fresh. Less mess and in any case, probably time to change your fluid. Press the pistons fully back into the calipers too, empty out the dirty fluid. You can use a vacuum bleeder then with no need to press the pedal etc.

 

[nick_the_fish]

ok thanks @Chris . So pipe on bleed nipples and let gravity do the rest (to drain)?

If not using the brake pedal, what is the best way to get fluid back into the system and get all the air out?

and on the subject of the master cylinder, is it something that wears out, and should I change it ahead of a (potential) 100k mile trip? (just to be on the safe side)

 

[Chris]

Did you actually read my post Nick? Vacuum bleeder. Every time. I have just taken the calipers off my quad this afternoon. Used the vac bleeder to suck it all out so there's none to drip. Keeps the drive clean and missus happy. Filling is the same procedure but keep the reservoir topped up as you do it. It wastes less fluid that pumping the brakes too. I find with mine that it tends to suck the air out easily but once it hits fluid, it slows up. Air is easier to pull out I guess. I can't see what's going on in the lines, but it's almost as though it pulls the air through the fluid. Anyhoo, one man job 30 secs per wheel and you're done.

Well the MC can fail yes, which is why they sell spares ones of course. But the pedal in normal use only travels so far before pressure stops it. When you bleed with the up down method, the piston is pushed the full length of the MC. Often this unused area is full of crud, dirt and isn't as polished as the rest of the cyl. There are two sets of seals on the piston - one for each circuit and the idea is that they can pressurise independently of each other. When you rough up the seals, it allows fluid to pass over the piston when you press the pedal.

Anyway you get the idea. You can do the up and down method but put a block of wood under the pedal to limit travel.

As for swapping it out, it's not a bad thing to do or at the very least put one in the spares box.

 

[Towpack]

I guess everyone has a method they prefer. I’d screw the lid on the reservoir over a piece of polythene or cling film to airlock the system and stop fluid gravity draining, change all the hoses, then refill/bleed the system with either a vacuum tool as mentioned or a pressure bleeder. I use an old Gunsons EasiBleed. Connect the thing up then just go round all the nipples, in order, until new fluid appears. No need to keep checking and topping up the reservoir.

 

[guyc]

ok thanks @Chris ..... a (potential) 100k mile trip? (just to be on the safe side)

That is some trip. If that is the right number of zero's, I'd be changing everything (just to be on the safe side).

 

[uHu]

...and on the subject of the master cylinder, is it something that wears out, and should I change it ahead of a (potential) 100k mile trip? (just to be on the safe side)

What kind of master cylinder do you have on the 105? Is it with an electric booster like on the 100 or a vacuum one like the 80?

So, you got 2 methods for keeping the hoses off for a week. Both will work, I suppose. But if you have the electric booster, it will take some more time and effort to get the air out of the booster and the abs-circuit after draining, so in that case I suggest not draining it. Also, with the electric booster, the bleeding is so easy and fast that there is no need for a vacuum tool, unless you have it handy already.

The issue with avoiding using the full stroke of the pedal is something I've heard about, but never seen as a problem. If the full stroke can not be used, then that's a problem that has to be dealt with, and not avoided. On my 100 the pedal always goes to the floor before I turn on the ignition, and I've been bleeding with full strokes without any problems.

 

[Chris]

Maybe because a 100 series isn't as old. If you've been bleeding it (why?) then you've probably kept the MC clean. But on something that's maybe 20+ years old and has never been pushed to full stroke then it's a fairly common problem I can assure you. Nick's 105 is pretty basic - I've worked on it. The booster really doesn't have anything to do with what he's trying to achieve.

 

[chapel gate]

What kind of master cylinder do you have on the 105? Is it with an electric booster like on the 100 or a vacuum one like the 80?

So, you got 2 methods for keeping the hoses off for a week. Both will work, I suppose. But if you have the electric booster, it will take some more time and effort to get the air out of the booster and the abs-circuit after draining, so in that case I suggest not draining it. Also, with the electric booster, the bleeding is so easy and fast that there is no need for a vacuum tool, unless you have it handy already.

The issue with avoiding using the full stroke of the pedal is something I've heard about, but never seen as a problem. If the full stroke can not be used, then that's a problem that has to be dealt with, and not avoided. On my 100 the pedal always goes to the floor before I turn on the ignition, and I've been bleeding with full strokes without any problems.

I've also never suffered any consequences from many years of the old pedal to the floor, "open, close, open, close, close, I mean open." etc etc technique.

 

[nick_the_fish]

OK brilliant thanks guys.

Did you actually read my post Nick? Vacuum bleeder. Every time.

For some reason I read that the vacuum bleeder was for refilling the system, but if I can use i for draining the system as well then i'll go with that.

What kind of master cylinder do you have on the 105?

Honestly don't know, but there are no wires going to it and there is no ABS on the truck, so probably as basic as they come (as Chris says).

That is some trip. If that is the right number of zero's, I'd be changing everything (just to be on the safe side).

Thats the top side figure. It may be as low as 40K . We'll see how we are feeling as we go. We're not putting pressure on ourselves to do anything or go anywhere unless we are having fun.

I'll pick up a spare master cylinder to either take with us or swap out before we go.

 

[nick_the_fish]

Has anyone used a Gunson Eezibleed? I know its a pressure rather than a vacuum method, but I like the idea of it being small and could be taken away with you should you need to bleed the brakes while you're away.

 

[Scott]

Hi Nick, I used a Gunsons Eezibleed for years, but I now use a larger Sealey kit instead. Getting the Gunsons to seal on some master cylinders was the tricky bit (always use rags underneath the master cylinder to catch any leaks, keep the brake fluid off of the paint as it’s a paint stripper!), and I if I recall correctly the Land Cruiser was one of them.

The kit I now use (https://www.toolstop.co.uk/sealey-vs820-brake-clutch-bleeding-system-p10142) has the optional universal cap, which is carefully clamped against the master cylinder opening by a chain threaded underneath it. It works well and I use it on all brake systems I bleed (no helpers, so I need single man operation).

It’s not compact enough to take on a trip though. In those circumstances I’d use the old up down method, but not push the pedal too far down, in an effort to keep it in its normal operating range (people have suggested on here to stick an object under the brake pedal to limit its range in this circumstance, which seems a good call).

 

[nick_the_fish]

Thanks Scott,

That was the other one I was looking at. It has the added benefit of being able to control the pressure so that I don't have to run 45PSI tyre pressure through a 15 year old brake system.

 

[Scott]

45psi, that’ll knacker it! I always use to lower the tyre pressure in the tyre used to pressurise the Gunson for that reason. As you say the Sealey one is good for that reason, you can pressurise to just enough to do the job and leave it at that, reducing the risk of over pressurising the brake system.

 

[nick_the_fish]

So I removed the brake lines this morning. 2 on the front axle, 1 front axle to chassis (to be extended), 1 rear axle to chassis (to be extended) - all good so far, HOWEVER - on the rear axle there were no flexible hoses, the brake lines ran straight into the rear drum.

So, presumably that either means

1. there's no need for flexible lines since nothing on the rear axle/ brake interface actually moves
2. there are flexible lines inside the drum which I can't see (but why?)
3. There are no disc brakes on my rear wheels (in which case what are the lines there for?)

I am assuming 1, but can anyone in the know confirm for me.

Ta

 

[David]

If it’s like my troopy you have 1 flexible that goes to the solid then they go to the slave cylinder in the drum

 

[Chris]

Nick you can see all the flexible hoses on the braking system. They're only in locations where flexibility / movement is required between components. My Hilux is the same on the rear. Solid axle, flexible to the axle and then metal pies to the brakes. Hoses aren't needed.

 

[nick_the_fish]

Great, thanks guys. I thought so, but wanted to check.