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Hardway

Alternative Brake Vacuum Hose Source?

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At one point someone used to sell non-braided brake booster vacuum hoses.  Now the only hoses I see are braided which are technically correct but carry a premium price.  I have a '71 240z, built Aug. of '70 so according to MSA I need the engine side hose at ether $69.96 or $77.95 and the booster hose at $89.95.  After shipping this will be almost $200 for two rubber hoses.  I understand supply and demand, cost of development, manufacturing, etc. However at those prices the margins must be near 90%.

 

I took my two hoses to two different parts stores yesterday hoping to find something that would work.  Of course they did not have anything remotely close.  I am going to check two independent stores later this week and a NAPA on the other side of town.  Does anyone know of another source for these hoses?  I personally don't care about the braided cloth on the outside but I need to replace my hoses as they are the originals, very brittle, and quite ugly.

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I've looked at Black Dragon's catalog, page 55, they show the engine side for $55.  Called my Nissan parts guy and he says there none from Nissan on both hoses.  I was telling him about MSA having them and he said they probably get them formed up at some type of hydraulic hose business for resale.  Maybe worth a phone call to a local hose shop to see if they could form some up for you?

 

Good luck.

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I've recently bought one from Ryan at Z car depot for $75 and had it shipped to the UK with some other bits and pieces, I agree that seems quite a few $$$ for a hose but as you say it's suppky and demand, I couldn't get one over here.

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Hardway, from the pictures in your signature thread, it looks like your engine side master vac hose is the early style that

plugs into the end, rather than the top, of the balance tube, correct?

 

I may be able to help you out on the master vac side hose, and the engine side hose, only if it plugged into the top of 

your balance tube.

 

What I have are lightly used rubber style OEM hoses that are in new condition, except for the clamp impressions.

 

PM me if interested.

 

Dan

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Thank you for the info and offer Dan.  My engine side hose plugs in to the end of the balance tube, unfortunately not on top.  If the booster side hose is the same I would be interested in it.  If needed I can shoot a picture of it tomorrow and post it.

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Thank you for the info and offer Dan.  My engine side hose plugs in to the end of the balance tube, unfortunately not on top.  If the booster side hose is the same I would be interested in it.  If needed I can shoot a picture of it tomorrow and post it.

If I recall correctly, there is a threaded hole on the top and the side.  Just move the plug to the top and plug the other hole.  That's what I did on my '71.

Edited by Marty Rogan

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Thank you for the info and offer Dan.  My engine side hose plugs in to the end of the balance tube, unfortunately not on top.  If the booster side hose is the same I would be interested in it.  If needed I can shoot a picture of it tomorrow and post it.

I believe that the booster side hoses are all the same up to 6/72.  As for the balance tube, or engine side hose, as Marty mentioned, some balance tubes had an optional

plug on the top of the balance tube as well as the end.  If your balance tube has this optional plug on top, and you wanted to move the location of your engine side hose

to accomodate the hose I have, then my hose would work.  As your cars build date is 8/70 which is approximately the model year change-over date from '70 to '71, this is 

most likely the change-over for this hose configuration.  If you are concerned about originality, there is a general consensus that parts usage became blurred as to what

was correct during model changes, but this would be your call.

 

Dan

 

This is a reference for dates from our parts CD.

 

D:\ZCD\BASEQ3\PAK\YODA\S30_5c.pdf

Edited by AZ-240z

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I checked my balance tube and unfortunately it only has two bosses cast in to the top rear of the tube, no holes.  At this point the only hose I could use is the booster hose.  I will PM you my contact info so we can discuss it more there. 

 

I called a custom hose builder here in town and they do "mold" or form hoses.  He knew what I was needing but could not recommend a place.  For now, I will keep hunting for an engine side hose.

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i used some air hose for the engine side on my conversion (my balance tube is also connected at the end). it's the right diameter but the manifold heat softens it to where it collapsed from the vacuum, so i put a cut and formed a piece of old fuel rail tubing to make the same sweep and slid it inside the air hose to support it. works just fine but definitely not "oem" (then again very little about my car is at this point).

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Might be easier to find and install a different balance tube than to find a early-style, engine-side vacuum hose that's in good condition.  I have the same issue with my 5/70.  I measured both the OE hose (tattred braiding, ok hose) and the brass fitting and found that they're 'odd' compared to all of the other S30 hose fittings:

 

Hose ID:  9.5mm

Fitting OD:  10.75mm

 

Hose 'stretch' over fitting:  13%

 

Hose Wall:  about 4mm  (compares with 3.5mm measured for an OE coolant hose... | 10% thicker wall)

 

 

Unfortunately, all that`s out there in the way of braided hose is 9mm or 11mm (ID), both with a coolant-hose-type wall thickness.  Neither is suitable for the Nissan OE fitting -- one is too small, the other too big, both are too thin.

 

But:  An 11mm hose with a formed metal-tube liner/shaper might work -- if you properly seal the two ends over the slightly-too-small OE fittings.  Just thinking out loud, here...

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What about using some copper tubing inside the hose, bent the way you need.  Put it in an oven or use a heat gun to "form" it.  I've never done that but how do the hose shops do it?

 

Quick google came up with this off a Corvette forum;

 

icon1.gif Re: How do I make custom-formed rubber hoses? (CentralCoaster)
I don't think a heat gun will work very well. The heat is too hard to regulate.

I have not tried this, but it should work. Slip the hose over some soft copper tubing. The copper tube should go thru the entire hose length. Use a little water/soap to make it slip on easier.

Bend it to the shape you want then place in oven at 325 degrees for 10 minutes. Take it out and let it cool slowly.

I am guessing on the temp / time here. Obviously, too hot or too long will totally melt it. Too little and it won't change shape. You may want to experiment with a small piece of hose at various temps and times to see what happens before doing the final part. I guess the right temp will be 325-400 degrees but check the temp rating.

You may want to do this while the wife/significant other is out shopping (smell).

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I wanted to provide a follow up to this thread.  AZ-240z (Dan) is the MAN!  I purchased the booster vac. hose from him and he offered to make the engine side hose.  After we traded some emails, measurements, and pictures back and forth the hoses arrived at my door step. 

 

EngineVacHose02.jpg

 

To say I was impressed is an understatement.  The hose he made was an exact replica of my old braided hose. 

 

HosesTogether01.jpg

 

HosesTogether02.jpg

 

With both hoses installed it really cleans up the look of the engine compartment.  I personally think the engine side hose fits better than the original did.  It certainly follows the lines of the engine components very well.

 

NewHoses02.jpg

 

NewHoses03.jpg

 

Thank you again Dan!  This is another shining example of how great the classic Datsun community is.

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I know this is a really old post, but I thought I would follow up with what I learned. I tested baking hoses and it works quite well, here is what I did to form my own brake booster hoses.

I started by testing a few pieces at 350 degrees for 3 different times with 1/4 od soft copper pipe to hold the shape, the first one I tested with my tire pyrometer to see how hot it was (hotter than 200 degrees in the middle of the rubber and that is the limit of the pyrometer, so I didn't test the others). I decided to go with a 7 minute bake, as you can see all three held their shape, 9 minute stunk a bit more so I went with the middle of the 3 for my final bake.

I used 3/8" fuel injector hose which fit perfect, and has thicker walls than some of the other vacuum/fuel line hoses. For the real hoses I greased the copper tube so it would be easy to get out. I baked at 350 for 7 minutes, and the hoses stayed quite nice, not quite as tight as the factory lines, but they kept their shape well enough for what I needed.  I think the trick is to  bend them a little further than you need, and when dipping them in water, to cool them, hold the hose a little tighter than the tube holds it while pinching the other sides so it doesn't have a tendency to crush to get perfect bends. 

Well, that is what I did and I am satisfied with the results, it gave me a good looking formed hose without the cost of the braided ones, and if I need a new one down the road, I can easily make one for like $15 worth of stuff.

The integrity of the hoses looks great, but I didn't test them in any way other than driving it around. I totally recommend this for vacuum line hoses, but I would want to test a little more before using this method for fuel injection or other higher pressure and higher risk applications.

IMG_3747.JPG

IMG_3749.JPG

IMG_3748.JPG

Edited by bingo
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Thanks for blazing the trail.  I may give this a try with some straight braided hose that I have on hand.  The early-style engine-side brake vacuum hose is a hard item to find.

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You can also use that same size copper tubing with both ends open, insert it into the full length of the hose, bend it to shape then install just as it is with no baking.  The copper tube has to be about 3" shorter than the hose so there is room enough on either end for the hose to slip over the nipples.  There is more than enough space inside the copper tubing to accomodate the vacuum needed by the booster.

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