the flyin' scotsman

after many years of ownership and use the hose split on my Motive bleeder.

What hose is compatible with brake fluid and what clamps should be used?

dr bob

Malcolm -- I use a fabric-reinforced hose available at the local Home Depot, and have replaced it a couple times now when it started to look tired. There have been warnings about the exploding unreinforced Motiv vinyl hose for a while. A burst hose with a quart of brake fluid under pressure can do a lot of damage in a few seconds. Worth it to change it regularly for sure!

StratfordShark

I love my Motive Bleeder, bought when first owned 928 in 2006. Was especially valuable recently after two big brake rebuild jobs on current S4 and family Saab.

But I'm paranoid about possible hose failure, so last few occasions have been using it dry. Means keeping eye on reservoir and topping up on a really big bleed (and after bleed finished back to max), but no anxiety in use or managing fluid in hose at end of bleed.

dr bob

I appreciate the concern folks have, especially if they are using the original vinyl hose or an exact replacement. The deterioration of the hose is continuous over time, not something that happens instantly with new hose. If your hose is still clear and flexible, no worries. As it deteriorates it goes yellow well before there's any serious risk of failure. I bought ten feet of hose when I made my bleeder out of a small garden sprayer, enough for three lengths. When the original started to look ugly, I put a new piece on.

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Ultimately I changed mine over to use a short section of coiled poly hose, the kind you might use for compressed air. The downside with that is that I can't see fluid or bubbles in the hose as one can with the clear or translucent hose. But it works great and no risk of vinyl hose blowout.

Pics from original build with the reinforced hose, then after the upgrade to the coiled poly hose:

the flyin' scotsman

thanks dr. bob............off to HD.

I also like the idea of having the quick disconnect making it easier to install/ remove.

Now to get the old clamps off.

dr bob

The QD also allows one to rotate the cap to tighten it with the hose attached. I end up pumping the tank a little while holding the cap up high, so the air in the line is purged. As soon as I get fluid up into the cap, the QD is disconnected and the line stays packed with fluid. Then on to the car.

For others playing along at home, I cover the entire fender, and inside the engine bay, with plastic taped over everything. An old sacrificial bath towel is under the master cylinder to soak up any possible dribbles. I've not yet had any fluid spills but that doesn't mean that one isn't hiding, waiting for the time I get cocky and decide i don't need the plastic on everything. Black lawn and garden trash bags do the plastic covering duty, held in place with blue painter's tape (no residue). No such thing as "too cautious" when you have brake fluid under pressure.

On the modified sprayer, everything is as-original inside the tank. The original had a hose over a barbed connector, captive under a nut that fit over the threaded boss on the outlet nozzle. For the poly hose fitup, I threaded that boss internally with a 1/4" NPT tap, and added the simple 1/4 NPTM x 1/4 NPTF adapter that I found at Harbor Freight. That completely eliminated the vinyl hose from the unit. Perhaps a similar modification can be made to the Motiv bottle?

Tom in Austin

I had the split-hose experience with mine and it was not pretty ... brake fluid sprayed everywhere.

Called Motive and cussed them out, they sent a new clear hose. Would love to hear about a better hose we can change to!

WALTSTAR

How much are you guys pumping up the bleeder? You dont need enough pressure to cause a catastrophic explosion.

dr bob

I just add enough pressure to get the fluid flowing. Too much and the reservoir starts to pull out of the master cylinder grommets. For 5-speed cars, too much also risks popping the infamous blue hose between the reservoir and the clutch master cylinder.

"Catastrophic explosion" is a big term for what seems to start out as a split hose that dribbles brake fluid over whatever the bleeder happens to be sitting on. Unprotected fender? You are on the other side of the car, hunkered down with you attention on the caliper and why fluid may not be coming out there. Meanwhile, the split hose is a catastrophic leak. Same damage as the explosion without the sound effects I guess.

Matter is solved for me with the poly hose that doesn't suffer from brake fluid contact. The bottle sits on the floor, usually in a dishpan, so if there is a leak at that end it's not dangerous.

Somebody post a picture of the Motiv bottle and their hose connection method. mebbe we can come up with a similar fix for theirs.

skpyle

Hmmm...these are all excellent ideas.

My motive bleeder still has the original hose and attachment method. However, I have a female QD on the end. Mainly because I have different caps for different vehicles. Each cap has a short hose and a male QD. Makes swapping a snap.

I will look into dr bob's method of attaching the hose, and go from there.

Captain_Slow

Very timely...A few months ago I found my Power Bleeder hose split longitudinally. Kinda weird how it failed that way. I think it was about 10 years old.

dr bob

That's the common failure mode, apparently. So how did you discover the split? Hopefully it was during inspection prior to spraying brake fluid out of the split.

For those playing along at home, the original hose is a non-reinforced clear vinyl hose. It's great when new because you can very easily see when the hose has liquid in it, so you can avoid accidentally pumping extra air into the master cylinder. On one routine fluid flush I inadvertently let the fluid in the tank run low, and pushed some air bubbles into the system. Not Good. It took a bunch of work to get the ABS unit cleared of the bubbles. The coiled poly tubing I installed requires diligence because you can't see what's going through it. My workaround is to dump and extra liter of brake fluid into the bleeder tank, and use liter brake fluid bottles to receive the old fluid. By the time my bottles start to get full, I know I'm done with what's in the bleeder tank. For those with Motive bleeders, plan to put new hose on every year and you'll probably be just fine.

hacker-pschorr

I used whatever tubing fits from the local hardware store. I never add fluid to mine, it's just a pressure vessel so compatibility with brake fluid isn't a concern for me.

the flyin' scotsman

thanks for your inputs dr. B..........fully repaired my Motive bleeder using HD components including a QD.

I went with the cheaper see through hose which I'll change frequently........$6 for 20'

linderpat

My power bleeder has never worked for me. Bought it from one of the reputable 928 vendors years ago, and it simply never worked. I believe it is because the cap is the wrong size. But since it was sold by one of ours, I would think that piece would be correct.
I use the wife for help.