NAPA and German Brake Booster Vacuum Hose

[Oregon72]

OK, I sat there and pissed off the NAPA guy this afternoon. I must really have been annoying. Well, I need to hunt down a vacuum leak in my brake booster and I'll be replacing the 35 year old brake booster lines.

Told the guy I need reinforced brake servo/booster vacuum hose. The strong stuff please sir. We he says he has just the right thing and pulls out what is labeled as "1/2 inch (12.7mm) Premium Heater Hose made in USA by The Gates Corporation". He says that this is what they are using for hose and is good for brake booster lines. I asked him if it is strong enough not to collapse from the vacuum because I specifically need strong reinforced hose. He says that it has two layers of nylon braiding inside the rubber and that the vacuum from the engine isn't really that strong anyway and definitely not enough to collapse the hose. Says he can order the specific brake booster type hose, but says it is not as robust as the Premium Heater Hose he had right there (not sure if this was the truth or not). I eventually caved and bought it not really knowing if it was right. (5 ft cost me under $10.00- seems way cheap).

I need confirmation before I go and start installing it, what are your thoughts? Will this work alright? How extreme is the max vacuum force that is being applied to this hose anyway??

[Amskeptic]

"1/2 inch (12.7mm) Premium Heater Hose made in USA by The Gates Corporation". Will this work all right?

Due to the relatively short runs of hose, you should do OK. I do not know if the heater hose is gas vapor resistant, but give it a try while you keep a source for the correct stuff on stand-by.
Colin

[satchmo]

I would take off your old hose and measure it. Then call BusBoys and get the good stuff in the exact length you need. Here is the part number and price. It is expensive, but it has the wire re-inforcement you seek:

N 20390.12 Hose - High Pressure Rated For Servo Vacuum, Bus/Pickup/Vanagon 71-91 $12.25 per foot

Years ago, Colin helped me replace some brake booster hose on my bus during an IAC visit. We found some suitable hose at the FLAPS, then spent about an hour reaming out the ends of the hose so it would slide on to the nipples. It worked, but it probably didn't save me money in the end with all the time I spent making it fit.

Just my two cents. Tim

[Bookwus]

Hiya Tim,

.....N 20390.12 Hose - High Pressure Rated For Servo Vacuum, Bus/Pickup/Vanagon 71-91 $12.25 per foot.....

For what it's worth (I'm thinking about $5.25 per running foot) I can get OEM 12 mm vacuum hosing (yep, the braided German hosing) for just about $7.00 a foot.

[Amskeptic]

Hiya Tim,

.....N 20390.12 Hose - High Pressure Rated For Servo Vacuum, Bus/Pickup/Vanagon 71-91 $12.25 per foot.....

For what it's worth (I'm thinking about $5.25 per running foot) I can get OEM 12 mm vacuum hosing (yep, the braided German hosing) for just about $7.00 a foot.

With steel wire reinforcement in the internal diameter?
Colin

[Bookwus]

Hiya Colin,

Yep, steel reinforced.

[Bookwus]

Hiya Troy,

The vendor is BelMetric an outfit back in Massachusetts. They really don't want to sell to private parties (they are a wholesale jobber) but will do so if you buy a minimum.

I'm thinking that you and I might buy a lot togther and split it up. I do have a sample of the stuff if you'd like to look it over.

Colin, anybody else, want in on a group buy?

[Bookwus]

Hiya Troy,

This stuff is really quite hard to locate. I drive an AutoStick which also needs this 12mm reinforced hosing. In the course of moderating an online forum focusing on AutoSticks, we (all the folks over at that forum) have only located one source for this product - BelMetric. Minimum from BelMetric is 5 meters.

I can guarantee you that no reseller here locally will have this hosing.

[dhoch14]

Troy, that is the same hose that I'm using. It seems to work fine.

-dave

[Bookwus]

Dick & Jasan,

You guys will have to let me know how much hose you'll need/want. I don't have the brake booster sytem on my 70 and I have no idea of length covered/needed.

BelMetric sells by the meter, so, for example, if you need 5 feet you'll wind up buying 2 meters. The going price is about $22 per meter. Add in splitting the shipping costs and I'd guess your cost per foot will be around $9 a foot.

If you get hung up on having to order extra hose (because of the meter business) I might be willing to buy your surplus providing I have a couple of extra pennies around.

Still interested?

[Bookwus]

Hiya Jasan,

I'm thinking you'll have to crawl underneath and measure it.

By coincidence Colin was just a couple of blocks from me today. I showed him the hose (meets with his approval and he's in on the deal) and asked how much he'd need. He thought it would be about 5 feet but did mention that the brake booster changed positions during the years so you'll need to measure to be sure.

If those of you who are interested can get me your needs quickly, I can get the order out to Belmetric early next week and we can get it here and in our hands with some dispatch. I'll front the order and collect from youse guys later when we disperse the goods.

[Oregon72]

Colin said I needed to fix this brake booster vacuum leak before I drove the bus anymore and I really wanted to drive the bus, so I went ahead and replaced the original hose with the NAPA hose. The original VW factory hose I removed was very dry rotted and crusty. It is braided with cloth on the outside and has thin wire within the rubber. The 1/2 inch NAPA hose is an easy slip on fit and provides a nice tight connection with the decent hose clamp. I think the VW original was a 15/32" size so just slightly under 1/2 inch but the fitment is fine.

As for the length, For a '72, you're gonna want just a little over 5 feet. Not sure if all the bay window buses had the same length but I had 5 feet exactly and it just barely made it and I could have used a couple more inches (insert Morningwood joke here ).

[dtrumbo]

Measuring the length of the bus from the booster to the firewall is 10 feet. This was done by just laying the measuring tape on the floor running from about where the booster is to about where the firewall is. Adding the 3 feet of length in the engine compartment brings us to 13. That said, I think some fudge should be added due to my non-precise measurements. I think a couple of feet should do which would bring us to 15. That converts to about 4.5 meters. If you need to go in whole-meter increments, I'm down for a full 5 meters. This is probably the safest way to go as it will be cheaper in the long run to not use 2 feet instead of not being able to use 13 feet because it's too short.

For what it's worth, the hose that's in my bus appears to be a hard black plastic hose, not cloth braided or anything like that. Perhaps a PO has replaced it with this so-far suitable substitute.

[Amskeptic]

Measuring the length of the bus from the booster to the firewall is 10 feet. This was done by just laying the measuring tape on the floor running from about where the booster is to about where the firewall is. Adding the 3 feet of length in the engine compartment brings us to 13. That said, I think some fudge should be added due to my non-precise measurements. I think a couple of feet should do which would bring us to 15. That converts to about 4.5 meters. If you need to go in whole-meter increments, I'm down for a full 5 meters. This is probably the safest way to go as it will be cheaper in the long run to not use 2 feet instead of not being able to use 13 feet because it's too short.

For what it's worth, the hose that's in my bus appears to be a hard black plastic hose, not cloth braided or anything like that. Perhaps a PO has replaced it with this so-far suitable substitute.

The booster does not change position, the take-off from the engine does, '72 from the right side, later years from the left.
There is a metal pipe along the underside that carries the vacuum to the booster, so you only need the runs from engine to pipe and pipe to booster.
Colinmustrun

[dtrumbo]

O.k. so after actually crawling under the bus and looking at the hose instead of assuming, I have revised figures.

First, it appears that the hard plastic hose is original. Each end has a bell-shaped flare to fit over the connection and then is clamped. Nice, but I'm sure long since NLA which is why we're having this discussion.

So, on a '78 bus, the length between the plenum and the firewall, including the check valve is between 2 and 3 feet. Let's use 3 feet for safety.

Then, from the firewall to the pipe that runs the length of the bus is also about 3 feet.

The final piece from the forward end of the pipe to the booster is between 1 and 2 feet so again, let's use 2.

That brings the total to nearly 8 feet which is just under 2.5 meters. Again, if we need to round up to whole numbers, 3 meters will be plenty.

Thanks Mike and let us know what you come up with.