Sam Buchanan

I use a Carter pump located just forward of the fuel tank as the only pump. The mechanical pump was removed and a blockoff plate installed. This pump has been in service on my P15 for two years and I ran the same type pump on a carbed kit car for ten years. Flawless service in both applications, no return lines. If I wanted a pass-through pump I would install a Facet pump such as the ones I use on aircraft as a boost pump. The Facet pump on my RV-6 aircraft has been in service for 22 years, still clicking. I also used a Facet pump in the Chevy S-10 when the 2.8V6 was replaced with an engine that didn't have a mechanical pump. This is the 6v Carter rotary pump, have only used it as a primary pump, don't know how it would function pass-through.

Why would you run a return line? This is a low-pressure pump designed for use with a carb.

Why not use the Carter as your primary (only) pump?

You need three things to make this truck run. Compression Spark occurring at the right time Fuel through the carb You can scatter-shot your troubleshooting if you wish but the most productive route will be to take each of the above three and verify their quality. Easiest thing to check is compression--if decent then move on. If not, internal engine work is needed. I would then move to ignition. This involves voltage to the coil and distributor, points in good condition, gap and timing properly set, and healthy plugs. Then see if fuel is getting to the carb.....it probably isn't due to a clogged system.....repair as necessary. May involve a new fuel pump and/or carb overhaul....or maybe attention to the fuel tank and lines. But you can bypass these just to get it running. When you have compression, properly timed spark and fuel.......the truck will run. Oh....one more thing you must have.....a service manual.

Yes...your memory is faulty. ? If your tank vents properly with the mechanical pump it will vent with the electric, the tank doesn't know the difference. I think you are getting tangled up with something someone may have told you about a return line being necessary for an electric pump....but that ain't so.

A good electric pump can also function very nicely as the only pump.

N228

The reason why the aviation community frowns on fueling from plastic cans is the nozzle isn't conductive so a difference in potential between the can and airframe isn't reduced and a static discharge can ignite the fumes. However, I have burned a lot of auto gas in some of my lighter aircraft but the precaution I take is always using a Mr. Funnel. This funnel in addition to having a filter that water will not pass through is conductive and allows the can to safely achieve the same potential as the fuel tank. Another thing I've done when using a transfer pump is use a ground cable. A clip on one end of a 1/16" cable is attached to the exhaust stack of the airplane, the other end is attached to a length of stainless welding rod which is dropped into the can. Is all this necessary? Don't know...but so far no fires.

Even though it goes against many of the impulses I've demonstrated in my experiences with motorized devices, I think more now about the implications of physics that Mr. Newton explored a few years ago. If my P15 is brought to an abrupt and complete stop at 70mph there is four times the amount of energy to be dissipated than if the stop occurred at 35mph. The primary way the old car can shed that energy is by totally and catastrophically compressing and/or sending bits and pieces in multiple directions. Of course my body will still be following Mr. Newton's implications and attempt to continue its current trajectory at 70mph. The p15-d24 forum will have one less subscriber. In spite of all that, I really enjoy cruising my '48 between 50-60mph (with a seat belt), but I try to drive with the same mindset I used many years ago while piloting motorcycles!

I think that is a valid assumption. Have a part number and source?

This is just a guess on my part, but I suspect if the hose has some degree of conductivity it is due to the carbon composition, not an active conductor such as copper. It wouldn't take much conductivity to drain a static charge to achieve neutral potential. But I have no idea if such a hose is available. My go-to site for out-of-the-ordinary materials is McMaster-Carr and they list a hose that is conductive due to its carbon composition: https://www.mcmaster.com/hose/hose-and-hose-fittings/static-dissipative-high-pressure-braided-chemical-hose/ But that hose doesn't have any application for us. Interesting topic, maybe we got a charge out of discussing it. ?

Pretty sure the fuel nozzle is metallic (every one I recall seeing anyway) and the hose also has a conductor in it. This is so unbalanced potential will be neutralized when the nozzle touches the metallic filler neck before fuel begins flowing. I wouldn't be surprised if the proper hoses for our filler necks have some degree of conductivity. From what I've seen this is the difference between fuel transfer pumps (farm equipment) that are designed for gasoline vs some other liquid. The gasoline hoses and pumps are conductive which is more expensive than the non-conductive hoses and pumps used for petroleum products.

This is a point of concern in the aviation world but not sure if it applies in a practical sense to our vehicles. I don't play an electrical engineer on TV but as I understand the matter, the likelihood of a static spark is enhanced when the fuel filler nozzle has a different electrical potential from the fuel tank. This occurs in aviation because the high speed of the airframe (friction) through the atmosphere can result in an electrical potential building on the airframe much the same as when rain falls through a cloud (lightning). The aircraft pulls up the fuel station carrying its potential which is different from the potential on the truck...when the fuel nozzle touches the airframe.....pow! This is prevented by the strict use of a grounding cable which is connected to both the fuel station and airframe BEFORE fueling and this dissipates any difference of potential charge. A potential charge can also result from the flow of fuel through the nozzle and air as it enters the fuel tank if both are not properly grounded. We see a similar situation at our auto gas pumps. Ever seen the placard on the pump that states you must put your plastic lawnmower gas can on the ground before filling it? This is to assure the can has the same potential as the pump....leaving the can in the bed of your rubber tire insulated truck bed is considered bad practice. Will an explosion occur if these standards aren't practiced? Most of the time....no...conditions need to be in a small window to support combustion (low humidity so the spark occurs). But it only takes one spark to create a fiasco. I think the carbon in our car tires is considered to have enough conductivity to drain potential differences to ground so we don't worry about filling up the tank. But having the filler neck electrically bonded to the auto frame is not a bad idea. I stand ready to be further educated on this matter.

Cute story, but I fail to see what it has to do with crimping wire terminals.......but you tried. ?

Whoa....we're jumping to some (invalid) conclusions here. Read my post carefully....I didn't say the plastic terminals were mil-spec. Also, the photo you attached is a connector that is in NO way related to the terminals we are discussing. Let's be honest when we want to disagree..... ? Also, the photo I attached is the cheap terminals I used in my P15. But even the cheapies are nicely and securely crimped when a ratcheting crimper is used. Hey......if someone wants to solder terminals....knock yourself out. But it isn't necessary if all you want are reliable connections that are easy and quick to make with the proper tool.

I don't understand the dislike for terminals with plastic sleeves. Those terminals are preferred for every type automotive and aviation wiring I've ever done. The reason some may not like the plastic version might be due to using cheap, low-quality terminals.....I'm talking about the ones you find in the chain auto parts stores. Good terminals with plastic sleeves are designed to be used with ratcheting crimpers and provide strain relief of the wire without resorting to soldering which can introduce stresses in the wire if not done according to military standards (I used to be a certified instructor in military soldering on wiring harnesses and circuit boards). But even if you use the cheap terminals, and I do sometimes, all that is necessary is to visually confirm the wire is inserted all the way into the terminal--you can see the end of the wire next to the business end of the terminal--before crimping. If that is done, and the proper size terminal is used for the particular wire, and a good crimper is used, there should be 100% reliability of the crimp. The crimped terminals on the aircraft I built 23 years ago have been totally reliable, but I used good technique with high-quality terminals and crimper. Here is the terminal strip in the P15 that connects the turn signal switch to the car's harness.

I think that particular crimper in addition to Amazon is also available at Home Depot. I'm helping a friend wire his airplane, he has this crimper and it works fine. My crimper is a different brand which I don't recall and has served me well for 25 years of wiring several cars, boats and airplanes.

You need a ratcheting crimper for consistent crimps that will stand the test of time. There are several brands, the more expensive ones are probably better for commercial use, but the "consumer" grade crimpers usually work well. The advantage of ratcheting crimpers is they crimp the terminals the same amount each time and also crimp the insulator for strain relief of the wire. The cheap crimpers found in auto parts stores depend on the grip of the user, crimps can be either barely ok or abysmal.

Or just download this pdf that shows the direction of the adjusters: https://p15-d24.com/files/file/1-brakepdf/

This thread is currently running: https://p15-d24.com/topic/57640-brake-bleeding/ The answers to your questions are: Yes. Very. Motive Power

The best method I've found for my P15 is the power bleeder. Period.

The way we bleed our aircraft brakes is with a pump oil can connected to the bleeder with a hose. Fluid is pumped into the bleeder and back up to the master cylinder, pushing air as it goes. This process bleeds the system very quickly.

I think you're correct....I was referring to the photo Keithb7 posted.

I tried one of those vacuum bleeders that you hook up to an air compressor. I have a 5hp compressor so plenty of volume, but there was enough leakage around the bleeder threads to prevent sufficient vacuum for consistent results. I might have tried teflon tape on the threads but since I got the power bleeder the vacuum thingie has been collecting dust.

Excellent question. If the battery is healthy, the charging system is working as it should, there is no parasitic drain, and the car is driven occasionally, there should be no need to use a charger. If a charger is required, it is a bandaid that is covering up a problem in the electrical system.