I have read SO much on the PMD issues...I just bought my 1996 Suburban and the prev. owner said he's NEVER replaced the PMD. The truck have 266K on it, never replaced the IP or PMD. Should I assume this must be one of the few blessed PMDs that work right, or replace it now with a remote one, before I have a failure?

If you have or start to have PMD related problems you should get a remote unit.

If you want to make your vehicle more reliable you should start thinking about getting a remote unit.

Hi BK congrats on the Suburban,

I really like mine. I wasn't having any problems with the pmd but I bought a new one and the extension cable to get it off the motor. They seem to fail due to heat and if you go greasy like I did your going to add alot more heat to something that doesn't handle it well at all.

Mike
84' benz. 17K miles, 99 Burb. 6K miles

I bought this Sub to go 2 tank WVO, like yours. What WVO filter did you use, and what switching valves did you use? I am planning to go with a custom tank that fits along the frame rail underneath, and I have a 26 plate flat plate heat exchanger already. How well is yours working?

I bought my switching valves from Frybrid (hydraforce) along with the VW style heated filter they sell, it is pricey but they work very well. I also use a 26 fphe (Omar) along with HIH which may be overkill but it is what I used on my Benz, HOH would probably be fine. I would consider the dual thermostat conversion which the 97' and up went to (you don't want to over heat these motors). I had a bit of trouble with finding the right pump for the veggie side. I started with a Carter similar to the stock lift pump, then went to a mallory which also gave me problems and then I added the Carter to the pickup at the tank (the Carter pressurizes the fuel line and the Mallory gives it a boost, the Mallory is under the hood). I actually thought the IP was crapping out, with only one pump I would lose power or the motor would just die but restart. I have run the two pumps on the veggie side for several thousand miles now with no issues.
I really like this vehicle and it seems to run very well on the veg. oil, they do have a history of IP problems but it is a very good "fit" for my family. Frybrid has some good pics of the installs, it is a bit more than the Mercedes conversion but not all that difficult.

Let me know if I can answer any questions,

Mike

I am going to remote my PMD, and I had a question. On electronics, sometimes the transistor or IC chip is coated with a thermal conductive grease, and the grease makes the heat sink many times more effective. Does the PMD have a thermally conductive grease or adhesive on it? Anyone ever try putting some one between the PMD and the heatsink to conduct more heat away from the PMD?

Yes, we do.

The heat sink works well if it is not subjected to higher heat than the PMD itself generates. If it is then it will transfer heat to the PMD.:stirthepo

To bad they don't make a directional heat sink.:weld:

Stupid heat sinks..:smashfrea

To be safe I would go with a heath kit. Warranty is all I have to say. My rig had no trouble with its original owner, 3 months after I got it...it began.

They (who is this mysterious 'they' everyone always refers to?) do make a directional heat sink - it's called a Peltier junction device.

But, even it can be overwhelmed.

Do you think there is one of those Peltier junction device gizmo's that will work for an IC?

I used a Walbro 6065 back when I had a 6.5 in my Suburban It worked great for grease. In fact I still have it on my shelf. The thing I liked about it was that it seemed variable, and I could hear it really start to pump when I was on the fuel pedal, and slow down at idle. I have heard people have had problems with these pumps, but if you get a good one you are set.

Do you want to sell that Walbro on your shelf?

I am going to remote the PMD, and I have found a heat sink (9"x9"x2" fins). I was considering mounting a sink on both sides. Does the top of the PMD get hot as well as the bottom?