Vacuum hose controversy (1 Viewer)

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I want to make sure I am purchasing the correct size/quality vacuum hose for my 85 FJ60. Toyota part number Vacuum Hose - Toyota (90999-92004)
is available but 2 Toyota dealerships (online) say this does not fit my cruiser, 1 says it does. Or should I just buy some 3.5mm silicone hose on Amazon? This should be an easy one but isn't for me. Thanks for any input you can provide.
 
I think a lot of folks typically use McMaster-Carr hose. I used some local Auto parts hose for mine. Used 3MM which is tight but stays on better IMO. Seems to work fine but is pretty thin walled so I may source some of the McMaster-Carr stuff which is thicker and resists vacuum pull collapse.

Desmog guides list these McMaster part numbers:

3mm: 32 ft (McMaster Carr part #5041K22)
6mm: 12 ft (McMaster Carr part #5041K24)

I think OEM is 3.5 and 5.5 though so you may need to play with the above part numbers some. At least you can search on the MMC site for those numbers to get you started if nothing else. HTH

Edit: Link to 3MM MMC tubing here:

 
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I think a lot of folks typically use McMaster-Carr hose. I used some local Auto parts hose for mine. Used 3MM which is tight but stays on better IMO. Seems to work fine but is pretty thin walled so I may source some of the McMaster-Carr stuff which is thicker and resists vacuum pull collapse.

Desmog guides list these McMaster part numbers:

3mm: 32 ft (McMaster Carr part #5041K22)
6mm: 12 ft (McMaster Carr part #5041K24)

I think OEM is 3.5 and 5.5 though so you may need to play with the above part numbers some. At least you can search on the MMC site for those numbers to get you started if nothing else. HTH
Yes...the 3.5mm vs 3.0 mm has me minimally concerned but if folks here say the 3.0 works I have to figure it works. I will check out the McMaster site to se
SOR has some OEM vacuum hoses: Land Cruiser Emission Pumps, Belts Kits, & Vacuum Line

As I've found with my lines though, most are generic 3m brand cut to fit. A good many indie shops will use that as well.
I checked out SOR and it seems the OEM hose comes in 1ft lengths which I'm not sure is long enough for all applications but I will call them to confirm this.
 
Toyota genuine vacuum hose wears out after a long time. The ends can crack, it looses elasticity and eventually can lose its grip on vacuum pipes. -- That's why people replace it.

Silicone tubing (like the stuff sold at McMaster Carr) has none of those problems. The one downside to silicone tubing is that it's not as strong as the Toyota stuff. It's much easier to cut (frighteningly so) and not as heat resistant if it touches something it shouldn't.

After 15 years my Toyota vacuum hose was pretty shabby. After 15 years my McMaster hose was still like new.
 
Yes...the 3.5mm vs 3.0 mm has me minimally concerned but if folks here say the 3.0 works I have to figure it works. I will check out the McMaster site to se

I checked out SOR and it seems the OEM hose comes in 1ft lengths which I'm not sure is long enough for all applications but I will call them to confirm this.
McMaster list that hose at "max pressure 20 psi". Not being a mechanic I'll have to assume that is sufficient. But other sites like Amazon list the silicone hose as max pressure 65 psi....so I guess that is overkil
 
McMaster list that hose at "max pressure 20 psi". Not being a mechanic I'll have to assume that is sufficient. But other sites like Amazon list the silicone hose as max pressure 65 psi....so I guess that is overkil

Gates lists theirs at 25 PSI max. I cannot find specifics on the max PSI developed in the vacuum system of a working 2F motor right now. Seems like 11PSI is what sticks in my head but not sure at all about that so don't hold me to it. Emissions FSM shows like 8PSI intake vacuum at idle I think according to google converter tool:

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Maybe someone else can chime in on that.

Many people use the MMC hose so I wouldn't worry about the max PSI rating. Not sure what hose on Amazon you are looking at, but claims on Amazon as to product specifications are there to sell products, not really for accuracy. Lots of hose used for vacuum is multi-purpose so they maybe have higher PSI rating for use as a water hose or something. I have no direct experience with MMC hose but I know lots of folks use it on here. HTH.
 
The maximum vacuum the engine can produce on a gnarly engine braking event is maybe 36inHg for a brief moment. That is about 17psi equivalent when converted. The McMaster silicon tubing is much thicker than the Toyota tubing and has a smaller ID. I don't know what vacuum is required to collapse it, but I know the engine can't do it.

The PVC hose is a different story. Since it has such a large ID, special PCV rated (strong) hose is required. The vacuum will collapse even 3/8" fuel hose.
 
Was leaning towards McMasters.....but for this particular size and application it only comes in red. Although color should be the 2nd consideration after quality, there is so much darn vacuum hose on my 2F I can't see popping the hood and seeing red everywhere. The OEM at SOR is a non starter at $3.85 ft. They do sell aftermarket at $2.80 ft but that is still double what the red McMasters costs.. Decisions, decisions....
 
Was leaning towards McMasters.....but for this particular size and application it only comes in red.

Link I provided is in black. Different P/N:

 


FWIW, if you're in CR and there are parts houses that stock for German cars, like VW or MBZ, you can get the correct 3.5mm and 5.5mm but it's usually cloth-braided.

I didn't like the Silicone hose and ended up replacing all with OE, but for the cost I should have done the braided stuff. More scuff resistant.

If you need to buy online: RH3.5 - Braided Hose 3.5mm [N203531] - $6.63 : Bel-Metric, Metric Hardware, Metric Fasteners, Metric Bolts, Metric Nuts & Time-Sert Thread Repair
 
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Link I provided is in black. Different P/N:

Thanks for that link...yep, it's black so McM is back in the running. Gates looked good too except it was thin walled (5.6 mm total as opposed to others that are mostly 8 mm) What this means is beyond me. But I'm going to check out Boost Controller and that OEM number and then hopefully I can a friggin decision.
 
btw, that 90999-92004 is the correct part # .... 1 meter of 3.5 hose.
 
I also like the mcmaster carr 3mmID with 8mmOD. I have had it on my car for probably 20 years with no issues.

regarding the toyota parts numbering, back in the day, Toyota offered three different lengths and you purchased the size(s) you needed and cut it to the specific length: 300mm, 600mm and 950mm. you would buy the shortest length that would fit and cut it to the correct length. These old numbers are now superseded and maybe they don't cross reference back to the 1980's vehicles.

But I did search for the 950 mm (95411-19995) and it did supersede to the part number the OP listed. As far as I know, Toyota doesn't sell "by the foot", but you purchase the pieces--as many as you need. It's probably cheaper to get stuff off the roll.

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Gates lists theirs at 25 PSI max. I cannot find specifics on the max PSI developed in the vacuum system of a working 2F motor right now. Seems like 11PSI is what sticks in my head but not sure at all about that so don't hold me to it. Emissions FSM shows like 8PSI intake vacuum at idle I think according to google converter tool:

View attachment 2431530

View attachment 2431532

Maybe someone else can chime in on that.

Many people use the MMC hose so I wouldn't worry about the max PSI rating. Not sure what hose on Amazon you are looking at, but claims on Amazon as to product specifications are there to sell products, not really for accuracy. Lots of hose used for vacuum is multi-purpose so they maybe have higher PSI rating for use as a water hose or something. I have no direct experience with MMC hose but I know lots of folks use it on here. HTH.
generally PSI refers to positive pressure (pressure above atmospheric pressure). I'm sure the Gates rating is for pressure above atmospheric pressure. The Gates pressure rating is the maximum safe operating pressure such that the tube will not explode (from the inside out).

Vacuum is measuring negative pressure starting at atmospheric pressure to perfect vacuum. This is typically measured in mmHg. Tubing under vacuum conditions does not explode, but it can collapse. Collasping and exploding are different phenomena and one doesn't really relate to the other. The gates pressure rating doesn't matter if using the tubing for vacuum service.

The McMaster Carr tubing I have used has a 3mmID and 8mmOD (2.5mm wall thickiness). This is probably thicker than the OEM tubing. I have no problem with it collasping.
 
generally PSI refers to positive pressure (pressure above atmospheric pressure). I'm sure the Gates rating is for pressure above atmospheric pressure. The Gates pressure rating is the maximum safe operating pressure such that the tube will not explode (from the inside out).

Collasping and exploding are different phenomena and one doesn't really relate to the other.


Yes great point. I guess I was thinking at the time more in terms of what it would take to collapse the tube, assuming that exploding it and collapsing it would require roughly the same pressure. That's prolly a garbage assumption though. As you point out @2mbb, because we are talking about using this as vacuum hose and not pressure hose, the pressure rating isn't really useful here. This hose has varying uses and the rating stated would not really have anything to do with what it can handle when used as a vacuum hose. Vacuum and pressure are really opposites so trying to equate one to the other is silly. Again, thanks for pointing this out.

The basic point to the OP is that lots of folks use this hose with great results, so unless used completely incorrectly its gonna work. Click buy it now and get it going.
 
Yes great point. I guess I was thinking at the time more in terms of what it would take to collapse the tube, assuming that exploding it and collapsing it would require roughly the same pressure. That's prolly a garbage assumption though. As you point out @2mbb, because we are talking about using this as vacuum hose and not pressure hose, the pressure rating isn't really useful here. This hose has varying uses and the rating stated would not really have anything to do with what it can handle when used as a vacuum hose. Vacuum and pressure are really opposites so trying to equate one to the other is silly. Again, thanks for pointing this out.

The basic point to the OP is that lots of folks use this hose with great results, so unless used completely incorrectly its gonna work.
You guys are great! All this back and forth means I'm acually learning things that not long ago I had little interest in. Wonderful for an old dog like me!
 

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