The Diesel Stop banner

1 - 20 of 24 Posts

·
Registered
Joined
·
469 Posts
Discussion Starter #1
My vacuum reservoir, the metal can thing on the driver's side fender area, seems to be leaking... I have looked everywhere and nowhere seems to have this part listed. Anyone know where to get one? Or a part number? Being steel these tend to rot... can't believe they don't make a replacement...
 

·
Registered
Joined
·
1,722 Posts
They do - it's just not steel. Browse the JYs; any vacuum reservoir from any make/model will work - especially those with the same number of nipples as your truck's. The plastic dual-chamber version was used at least from '87-03, so they're very common:


(phone app link)


The single-chamber version is slightly less-common, but still easy to find.


(phone app link)


If you really want a steel one...


(phone app link)




(phone app link)
 

·
Registered
Joined
·
20 Posts
Why not make your own out of a couple of fittings and an old ammo can? Or fittings and pretty much any kind of container that would stand up to the use?
 

·
Registered
Joined
·
4,611 Posts
I made one with PVC pipe and end caps.
DENNY
 

·
Registered
Joined
·
469 Posts
Discussion Starter #6
Use thread adapters, and you even have a place to hook up the hoses


How big of a pipe? Like sewer abs pipe?

Not sure how to put in the thread adapter, or even what it is... end caps make sense but how do you add nipples that don't leak?
 

·
Registered
Joined
·
469 Posts
Discussion Starter #7

·
Registered
Joined
·
20 Posts
How big of a pipe? Like sewer abs pipe?

Not sure how to put in the thread adapter, or even what it is... end caps make sense but how do you add nipples that don't leak?
Drill a slightly undersized hole into the pipe cap. Probably best to do this after you have glued on the cap. And in the area where the cap and pipe overlap and are glued. That way you have double the thickness of plastic.


Screw the brass fitting into the hole. It will make it's own threads into the plastic.


Remove the fitting, coat the threads with silicone adhesive. Re-install the fitting. Let cure completely.


Done.


This works for making reservoirs for pressure up to several hundred pounds. It certainly should hold up to the less than 30 pounds of vacuum our systems must produce.
 

·
Premium Member
Joined
·
14,379 Posts
This works for making reservoirs for pressure up to several hundred pounds. It certainly should hold up to the less than 30 pounds of vacuum our systems must produce.


Science Nerd Alert. 30 pounds of vacuum feels like a typical American measuring unit. Like bullet velocity per square degrees Fahrenheit. Anyway, -30 (ok -29.92) inches of mercury is an absolute vacuum which is equivalent to -14.7 psi. In metric, that would be 0 torr (mmHg)


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
8,484 Posts
In the long run I think that I would make one out of PVC, but then I like doing that kind of stuff.

Other than that it looks like it is junkyard raiding time.
 

·
Registered
Joined
·
15 Posts
My vacuum reservoir, the metal can thing on the driver's side fender area, seems to be leaking... I have looked everywhere and nowhere seems to have this part listed. Anyone know where to get one? Or a part number? Being steel these tend to rot... can't believe they don't make a replacement...
https://www.fordpartsprime.com/ has a lot of hard to find, vintage and 'discontinued' OEM Ford parts. Check them out. I like buying on their site because their prices are cheaper than dealer.
 

·
Super Moderator
Joined
·
24,890 Posts
This works for making reservoirs for pressure up to several hundred pounds.
DO NOT use plastic pipe of any kind for a pressure reservoir, especially several hundred psi. The energy stored in the compressed air would be dangerously released if the plastic were to rupture. Even plastic shrapnel can kill you. :nono:
 

·
Registered
Joined
·
1,574 Posts
DO NOT use plastic pipe of any kind for a pressure reservoir, especially several hundred psi. The energy stored in the compressed air would be dangerously released if the plastic were to rupture. Even plastic shrapnel can kill you. :nono:
Plastic pipe within the parameters of its design ratings is perfectly safe to use. I would definitely NOT put several hundred psi on it, but for 20 to 25 inches HG,vacuum (lack of pressure) I don't see any trouble. If there were a problem that it couldn't stand it, it would simply collapse, or implode. Either way, I don't see a safety concern there, nor do I see a piece of schedule 40 pipe having any trouble at all.
 

·
Registered
Joined
·
20 Posts
DO NOT use plastic pipe of any kind for a pressure reservoir, especially several hundred psi. The energy stored in the compressed air would be dangerously released if the plastic were to rupture. Even plastic shrapnel can kill you. :nono:
I'll give you the shrapnel point. I wouldn't want to be around if it exploded.


But... PVC pipe is rated for it.


Read the pipe the next time you are in lowes or home depot.



Or just read these...


PVC Schedule 40 Pressure/DWV Pipe | Heritage Plastics | PVC Conduit | Electrical and Plumbing


https://www.aetnaplastics.com/site_media/media/attachments/aetna_product_aetnaproduct/204/PVC Sch 80 Pipe Dimensions.pdf
 

·
Super Moderator
Joined
·
24,890 Posts
I'll give you the shrapnel point. I wouldn't want to be around if it exploded.


But... PVC pipe is rated for it.
PVC may be rated for a specific pressure, but if you read your link closely, you'll see that the rating is for water (a non-compressible fluid) under non-shock conditions and only up to 73F, with a serious derating for higher temperatures. Even if you're within the rating with the applicable derating for temperature, bear in mind that plastic is flexible, and as such will store energy. Air is also compressible and stores energy as well, which all would be released in an instant if a rupture should occur. With water, pressure would be instantly decreased in a leak situation, and the danger of an explosive rupture is minimal. The maximum pressure applied in a vacuum situation would be ~15 psi (atmospheric pressure), so would be a relatively safe application.
 

·
Registered
Joined
·
20 Posts
PVC may be rated for a specific pressure, but if you read your link closely, you'll see that the rating is for water (a non-compressible fluid) under non-shock conditions and only up to 73F, with a serious derating for higher temperatures. Even if you're within the rating with the applicable derating for temperature, bear in mind that plastic is flexible, and as such will store energy. Air is also compressible and stores energy as well, which all would be released in an instant if a rupture should occur. With water, pressure would be instantly decreased in a leak situation, and the danger of an explosive rupture is minimal. The maximum pressure applied in a vacuum situation would be ~15 psi (atmospheric pressure), so would be a relatively safe application.
Yep. Every bit of that is true.


Makes you wonder why tons of people haven't died in the last 40 years or so, that have been making explosive potato guns. (Explosive meaning using propane or hair spray as an explosive medium, and a flame or electric spark as the detonator. And/or using very high pressures in air operated PVC spud guns...


We did the explosive kind, as kids. But they have developed some pretty sophisticated ones now. Explosive and air pressure type, both. Got whole forums dedicated to it.


And they get to some pretty high pressures. Like 800 pounds and higher. I think they choose specific kinds of pipe and fittings, but all of them can be found at Lowes...
 

·
Registered
Joined
·
1,574 Posts
Yep. Every bit of that is true.


Makes you wonder why tons of people haven't died in the last 40 years or so, that have been making explosive potato guns. (Explosive meaning using propane or hair spray as an explosive medium, and a flame or electric spark as the detonator. And/or using very high pressures in air operated PVC spud guns...


We did the explosive kind, as kids. But they have developed some pretty sophisticated ones now. Explosive and air pressure type, both. Got whole forums dedicated to it.


And they get to some pretty high pressures. Like 800 pounds and higher. I think they choose specific kinds of pipe and fittings, but all of them can be found at Lowes...


Like everything that has "flow" gas (compressed air and the like) will take the path of least resistance. In your 8oo pound example, was it 800 PSIG, or was it 800 pounds of thrust? There is a big difference. 100 PSIG can easily (in the right circumstances) produce 800 pounds of thrust. The potato in the potato gun reference is a movable object in an immovable cylinder. Pressure applied to the closed end would cause it to move rapidly. Don't stand in front of it. A closed piece of pipe (steel or plastic) will burst with enough pressure. Gasses compress making them especially dangerous, but if the pressure ratings of the pipe water or gas are not exceeded, then there is a much lower chance of a rupture. With PVC, you then get into the chemical makeup, which can seriously reduce its ability to hold pressure. Pressure is still pressure no matter what applies it, as long as the vessel is capable of withstanding the chemical makeup of the substance, there shouldn't be a problem. Provided of course you don't exceed the pressure capabilities of the vessel. For example, ASME ratings on air tanks are done with a water filled tank, then the tank is used to hold compressed air. Working pressures and burst pressures are different ratings. Working pressure (obviously) the lower of the two should NEVER be exceeded, you take your life in your hands when you do.
 

·
Premium Member
Joined
·
8,484 Posts
Yep. Every bit of that is true.


Makes you wonder why tons of people haven't died in the last 40 years or so, that have been making explosive potato guns. (Explosive meaning using propane or hair spray as an explosive medium, and a flame or electric spark as the detonator. And/or using very high pressures in air operated PVC spud guns...


We did the explosive kind, as kids. But they have developed some pretty sophisticated ones now. Explosive and air pressure type, both. Got whole forums dedicated to it.


And they get to some pretty high pressures. Like 800 pounds and higher. I think they choose specific kinds of pipe and fittings, but all of them can be found at Lowes...

If you take that potato gun and cap the barrel with a solid cap and not a potato you will see a big explosion. Even if you drill a 1/2" hole into the barrel to allow some gases to escape. It doesn't blow with the potato in it because as the gasses expand the potato moves out of the barrel. It would be no different if you took a rifle or shotgun and plugged the end of the barrel and didn't provide a large enough hole in it for the gasses to escape and then pulled the trigger. Large boom as the barrel is destroyed by the expanding gas.
 

·
Registered
Joined
·
20 Posts
You have to make a chamber, to hold the pressure.

Fill that chamber with that pressure.

Then you open a valve to let the air from that chamber push the potato plug out of the barrel.

I'm not saying it is a good idea to put hundreds of pounds of pressure into a chamber made from PVC pipe. But I AM saying that people have been doing it for decades.

This, although interesting, has become a sidetrack to this thread.

The fact is that a chamber made from PVC pipe will do perfectly well as a vacuum chamber on one of our trucks. With no danger whatever. Mount it where the vacuum chamber would normally be mounted, and in the same way, and you'll be fine.
 
1 - 20 of 24 Posts
Top