Serpentine Belt System


Summary of Parts
Part Sourced From Manufacturer / MPN
Alternator Summit Racing Powermaster #477681
Air Pump Bypass Pulley eBay (Performance Parts) Tuff Stuff Performance #1700
Crankshaft Pulley '93 F150
Crankshaft Pulley Spacer Summit Racing March Performance #1432
Reverse Flow Water Pump '93 F150
Water Pump Pulley '93 F150
Water Pump Gaskets CJ Pony Parts Edelbrock #EDL7254
Water Pump Bolt Kit CJ Pony Parts CJP #WPB8501
Universal Water Pump backing Plate Jegs PRW #5293029
Power Steering Pump Original on truck
Power Steering Pump Pulley '93 F150
A/C Compressor w/ Pulley '93 F150
A/C Compressor Manifold Summit Racing Vintage Air 045018
Alternator Bracket w/ idler pulleys '93 F150
A/C / Power Steering Bracket '93 F150
Heater return hose '93 F150
Fuel Pump Blockoff Plate Summit Racing Summit #SUM-402035
Serpentine Belt AutoZone Duralast 968K6 (6PK2460)

After installing the electric fans, the alternator belt would squeal until the alternator would spool up. When ever a heavy load was on the alternator (electric fans running, headlights on, air conditioning running, etc.), the squeal would often not stop. I'd tighten the alternator belt and things would be good for a while, then it would start squealing again. In addition, under heavy load, quite often the alternator voltage would struggle to get up to 12V and would not reach 12V at idle. Replacing the battery helped, but the belt would still squeal. After a while I decided it was time to move up to a serpentine belt system.

After completing this conversion the engine runs quiet (no belt squealing) and the system voltage hugs 14V, even at idle with all electrical systems active. Here's how the conversion went.....

With power steering and air conditioning, a new full belt system runs over $1500. I don't need a fancy billet, full dress system, so it was time to start looking through the junk yards. The block in this truck is a '68 302 with 28 oz harmonic balancer and a three belt crank pulley. Serpentine belt systems on the Ford 302 appear in the mid 80's and run through the mid 90's. In particular, it seems I needed a system from an '85-'93 Mustang, or an F series truck up to '95.

Fortunately, LKQ Pick Your Part in Rockford, IL maintains an on-line inventory of its vehicles. Watching for a couple months I eventually saw a half dozen potential candidates in their inventory - and they were new additions which meant there was a good chance they hadn't been stripped. One fine December day (50oF in Illinois!!!!) my daughter and I headed up there to look around. Truck #1 on our candidate list had a complete system still in place. We tore into it.....
Here's the on-line listing for the donor truck I found at LKQ Pick Your Part in Rockford, IL
The belt routing tag on the truck - mostly for historical purposes, but it confirms the system on this truck has what I was looking for.
Here's what we were looking at when we first came up to the truck. Alternator, air pump (I don't need this), water pump (reverse flow), crank pulley, A/C compressor and power steering pump. The serpentine belt was there, too, but sitting loose in the engine bay.
The alternator was siezed up and is only a 60A unit, but thinking I might need the pulley we pulled it and kept it - cheap insurance, but I ended up throwing it out.
The idler pulleys and water pump pulley look well used, but spin smoothly. I'm sure the rust will wear off quickly.
The A/C compressor looks to be good and I need the pulley, so it comes out. Later on I recognized this is transverse mounted and the one I currently have on the truck is longitudinally mounted - so I ended up using this compressor.
Frankly, when we were taking this stuff out, I had no idea what the unit under the alternator was. It's the air pump - part of the thermactor emission control system. We pulled this - again, as much for the pulley as anything. In the end this got thrown out and I replaced it with a new bypass pulley.
Here's the truck as we left it. All parts associated with the serpentine belt system have been removed. There's a couple hoses and electrical connections I wish we had pulled as well, but we didn't think of it at the time - more on that later.
Back home, here's what we have:
  • Front row: idler pulleys / alternator mount and crank pulley
  • Middle row: alternator, A/C compressor, air pump, water pump
  • Back: power steering pump with bracket for it and A/C compressor
The air pump was a total pain to take off the alternator / idler pulley bracket. The main mounting bolt was seized in place. No amount of break-free or heat would break it loose, and I eventually broke the bolt head off. Since I really didn't need this, the sawzall came out and I cut it out. Once it was out, I was able to remove it's mounting bolt. I probably won't be able to return this for the core refund!
The water pump was a critical acquisition. The V-belt system rotates the water pump clockwise when viewed from the front. However, the serpentine system wraps around the pulley the other direction and rotates the pulley counter-clockwise. Hence, I need to replace the existing water pump with the reverse-flow pump that came of the '93 F150. All the gaskets on the "new" water pump were shot, so a new set of water pump gaskets were ordered. Of anecdotal interest, when I pulled the backing plate off the '93 water pump, there was still casting sand in it (in the "unused voids")!
Here's a front view of the reverse flow water pump. The original fan clutch was a real pain to remove. Lot's of break free and a rubber mallet were needed to get it to break loose from the water pulley's center shaft.
Here's the V-belt system that was on the '56 F100. No air pump, with the alternator in the 7 o'clock position.
On the driver's side is the A/C compressor and power steering pump - fortunately in the same location as what was on the donor '93 F150.
The A/C compressor was un-mounted. It had been held in place primarily with turnbuckles!
The original power steering pump mount was removed.
Original (left at rear) vs. "new" power steering (and A/C compressor) mount.
Original A/C compressor mount (blue) vs. "new" mount (again shared with power steering pump).
Original alternator and mounting bracket. Side note - when I took this off, the 1/2" V-belt was about 3/8" wide - the drag, squealing and wear had worn it down significantly (and was why I needed to continually tighten the belt).
Original alternator removed.
Original water pump pulley removed.
Original water pump removed.
Original crank pulley removed. At this point, everything that's coming off is off. Or so I thought.
Trial fitting the new alternator mounting bracket revealed the oil check tube was in the way. I'm guessing the later 302s likely had these mounted towards the rear of the engine. After pulling this tube and trying to bend it to stay out of the way, I eventually broke the tube.
After a short mental debate I decided I can live without the tube and I sealed off the tube mounting hole. I may revisit this later. Note: there are plugs available to seal this hole in the timing cover, but as I'd broke the tube off but it extended about a half inch above the timing cover, I just crimped it and hit it with some high temp black gasket gunk.
With the oil check tube out of the way, the alternator mounting bracket slid in easily. I did have to bend the fuel line (which runs under the engine from the mechanical fuel pump on the driver's side to the carb inlet on the passenger side) a bit to clear the bracket.

This also shows the bypass pulley I bought to sit in place of the air pump. This is from Tuff Stuff Performance, product #1700, listed for a '90-'93 Mustang with 302. However, it appears to be a generic part for all/most Ford 302s of that era.

This is the new 200A, transverse mounted alternator I put in. This generates 140A at idle and should handle any electric demand I put on it. This is a Powermaster, stock #477681.
The alternator installed - it appears to line up fine. I did upgrade the ground going to the alternator with a 4 gauge strap.
Here's the old crank pulley I pulled out. Note the three mounting holes.
This shows the depth of the old crank pulley - significantly deeper than the serpentine crank pulley (below).
Here's the crank pulley for the serpentine belt system. Not only is it significantly "shorter" than the V-belt pulley, but this mounts with four bolts to the harmonic balancer.
I considered re-drilling the serpentine belt crank pulley to fit the three hole mounting and building some form of spacer. However, Google is a wonderful thing. I found this March Performance crankshaft pulley spacer / adapter (part number 1432). It mounts to the harmonic balancer with three bolts and allows a four bolt pulley to attach to it. Perfect, if not particularly cheap.
Here's the serpentine belt crank pulley and March Performance spacer installed.
Next in line is the mounting bracket for the power steering pump and A/C compressor. The first thing that jumped out is that the bracket mounted to the '93 302 using 7/16" bolts, whereas the '68 302 heads are drilled for 3/8" bolts. I'm not sure about drilling out and retapping the heads in the '68, so for now I'm just using grade 8 3/8" bolts.
The 3/8" bolts did rattle around quite a bit in the bracket holes (which are even large for 7/16" bolts). I picked up some thin brass tubing and slipped it over the 3/8" bolts to help fill the holes in the mounting bracket - creating sort of a home-made shoulder bolt.
However, when I tried to mount this bracket on the '68 block the next point of interference reared its head - the mechanical fuel pump is in the way. Presumably, by '93 everything was using EFI with high pressure electric fuel pumps in the gas tanks - hence there is nothing in this area of the engine to get in the way of the bracket. However, back in '68 it was all carburetors and mechanical fuel pumps. Once again, I had a choice - try to hog out the mounting bracket to fit around the mechanical fuel pump, or convert the truck to an electric fuel pump and delete the mechanical pump. I decided to change the truck to an electric fuel pump. This was not too hard a decision since I had an old Holley Red fuel pump sitting around that I pulled out of my Cobra when I upgraded it to an in-tank fuel pump.
Mechanical fuel pump removed.
A fuel pump blocking plate installed in its place (Summit Racing SUM-402035).
Trial fitting the power steering / A/C compressor mounting bracket with the mechanical fuel pump removed and with the power steering pump mounted (pulley not yet installed). There was nothing wrong with the existing power steering pump, so I just re-used the original one that was on the '56. The one off the '93 F150 was identical, so now I have a spare.
The A/C compressor temporarily installed to check fitment - looks good!
The water pump gaskets were backordered and took several weeks to come in - but come in they finally did. Using the reverse flow water pump from the '93 302, the new gaskets were put in place and the water pump mounted.
The water pump pulley was installed. Before proceeding any further, it was time to fill with coolant and check for leaks - which it did - massively! Coolant was running out from behind the water pump just above the lower radiator hose.
It was time for some internet searching. Thank you Hot Rod! This very good video shows the differences between a '60's era 302 timing cover/water pump and what is found in a '90's era Ford. The bottom line - if you attempt to put a '90's water pump on a '60's timing cover you'll end up with a massive coolant leak! In their image at left, "A" is a '60's era water pump, "B" a '90's era water pump, and "C" a universal water pump.
This shows a timing cover for a reverse flow water pump on left and the timing cover I have on the right (for a "normal" flow water pump). The timing cover on the '93 302 can also be seen here (it looks just like the image on the left).
What happens when one tries to mix/match water pumps and backing plates/timing covers? Massive leaks.
This shows my problem. This is the reverse flow water pump from the '93 302. The gasket is the correct one for the timing cover on my '68 302 - not a good match. In particular, the gasket and timing cover do not enclose the water outlet on the left in this picture. Take a guess where my water leak was.
Hot Rod pointed out that a "universal" water pump (backing plate) would fit either timing cover. However, at the time of their video there was no source for just a universal backing plate - one had to buy a full universal water pump.
Not so today - PRW now makes universal water pump backing plates for Ford 302 engines. I ordered one up. It comes with new mounting bolts (which did not fit my application (!!??)), but I had already ordered a new set of stock water pump bolts so I used those.
Mostly for future reference purposes, here's the reverse flow water pump sans the backing plate.
Reverse flow water pump; universal backing plate; new gaskets; new stock-like bolts - installed. The PRW universal water pump backing plate is thicker than a stock stamped backing plate, so the water pump pulley is set further out (~1/16" or so). This does not appear to be an issue.
Water pump pulley and hoses installed. To add a bit of re-inforcement to the water pump pulley, and to avoid having to cut down the pulley bolts, I cut off the base of the old fan clutch and use it as a "washer" to hold the pulley. The radiator was filled with coolant and the system re-checked for leaks - there were none (until I fired it up later).
At first I didn't recall saving the heater return hose "pipe" and fitting (attached to the upper alternator bolt). But, lo and behold, there it was in my pile of parts from the '93. This fit right in and helps control the plumbing around the serpentine belt system. This connects to the lower of the two 5/8" pipes on the water pump.
With the water pump installed (and not leaking), the A/C compressor and power steering pump mounting bracket was installed. I debated on drilling out and tapping the holes in the head to 7/16" (as was on the '93 302), but decided to stick with the 3/8" holes and bolts for now. If I see problems down the road, I can always drill/tap them then.
The power steering pump has been installed. Time to put the pump pulley back on..... next problem. There was not enough clearance in front of the power steering pump to fit the pulley installation tool.
The fan shroud for electric fan I installed is simply an aluminum box. Fortunately, the area in front of the power steering pump shaft is empty. So I popped a hole in the box to fit the head of the bolt of the pump pulley installation tool into.
While this worked, I need to have access to the head of the bolt to keep it from turning as I press the pulley onto the power steering pump shaft. I had to shorten the bolt ~1/2" (I guess I can't return this tool to AutoZone!).
Here we are in progress of installing the pulley. As can be seen, the hole in the fan shroud provides access to position the pulley installation tool, and with the main bolt shortened I have access to the bolt head and to the press nut.
The power steering pump pulley was pressed on until it was flush with the crank pulley (a straight edge was used).
With the pulley installation tool removed, here's the access hole I cut in the fan shroud.
A piece of aluminum tape covers the hole and restores the integrity of the fan shroud. Aesthetics are not a concern of mine on this truck - functionality is.
The last piece goes into place - the transverse mounted A/C Compressor from the '93 F150.
Before I hooked up the A/C plumbing I wanted to try out the belt and see that things were aligned correctly and working. The belt off the '93 F150 was routed through the pulleys, but ended up being too long. I guessed at needing a belt about 2" shorter, so hit AutoZone and bought a 6K968 belt - it worked fine. Good tension on the belt and the tension pulley is near mid-position. And, most importantly - all the pulleys line up with the belt installed.
I let fired the truck up and let it run. Voltage, at idle, with lights on was 14V. When the first fan kicked on there was a little drop, but not much. This is going to work fine - and no belt squeal.
After it got hot, there was one minor issue - the thermostat bypass hose was spraying out hot coolant from under one of the clamps. I had re-used the hose from the '93 302 and it was apparently time for a new one. A new hose from O'Reily's fixed the problem. No more leaks (that I know of).
Last step: hook up the A/C plumbing. But the manifold from the original compressor would not fit on the compressor from the '93 F150. Shown here is the manifold off the original compressor that has the hose fittings that work with the Vintage Air system in the truck. I needed this, or something similar to attach to the '93 compressor.
This is the back side of the original compressor.
This is the back side of the compressor I need to run (from the '93 which fits the transverse mounting bracket). The difference between the two compressors is subtle, but they are different enough that the manifolds do not exchange. Thinking these were identical, I did not initially bring home the A/C compressor manifold when I stripped the '93.
A return trip to the junk yard to acquire the '93 manifold showed why I didn't take it in the first place - it's a 5' long piece of tubing running between driers or some such. It does not have the screw-on hose fittings. The attachment bolts are different size; the '93 compressor has an alignment "stud" around the bolt, whereas the original is flush around the bolt; the original manifold has only one male alignment fitting around the #8 discharge fitting and O-rings around both fittings, whereas the '93 has male alignment fittings on both the #8 discharge and the #10 suction with no O-rings. Modify one or the other, or.....
Some Google searching turned up this manifold adapter from Vintage Air - probably the safest and surest approach - so one was ordered from Summit.
Summit Racing is in Ohio, so it's almost an overnight (free) delivery. The manifold fit just fine. I did find there were O-rings on the back of the compressor - they looked in good shape, so I added some mineral oil to them and put the manifold on. On the return trip to the junk yard I also grabbed the original electrical connection to the compressor. This had two wires - one to the compressor clutch activation circuit, and one to ground.
Job complete. Pulleys align. Runs smooth. All systems "go" (though I still need to get the A/C charged.
Again, job complete - alternator works fine without squealing!