Fuel pressure Regulator

[John 69 Camaro]

Hi, I am using Fuel Pressure Regulator, PN 3597 on my 3500 and when I apply suction to the vacuum hose going to the Regulator it doesn't hold. Does this mean my Regulator diaphram is bad and if so will the Regulator need to be replaced? Thanks, John

[J.Wagner]

If the diaphram is bad, you would have fuel coming from the vacuum hose. There could be a leak around the area where the regulator is crimped together. Apply vacuum and try to find the leak, it will have to be on the top half of the regulator somewhere.

[John 69 Camaro]

The only thing I noticed is that the vacuum hose connection at the Regulator actually turns in the housing. Is that normal or should I apply some RTV or glue to keep it stationary?

[J.Wagner]

It should not turn. Try the RTV or some epoxy around the base of the hose fitting.

[John 69 Camaro]

I applied some Seal-All, which is a glue that is Gas, Oil, and Water resistant and it appears to be holding suction. I still need to install the Throttle Body, Distributor Cap, Wires, and Valve Covers, so after I get it running, I let you know how it holds up. John

[John 69 Camaro]

I forgot to ask another question on the Fuel Pressure Regulator before sending out my last reply. Although I have a 3597 Regulator I did notice it looks a bit different then the picture on page 14 of the Installation Manual for the 3500. Mine has a 3/16 bolt with a 5/16 head going through the top center of the plastic housing. The picture on page 14 doesn't show this bolt. Do I have an older version and and do you know the purpose of the bolt? Initially I thought is was an adjusting bolt but I'm under the impression the 3597 Regulator is non-adjustable. Thanks, John

[J.Wagner]

The 3597 regulator is the original version that mounts between the fuel rails, we changed to a 3584 about 6 or 7 year back, it mounts on the end of one fuel rail. Both have the same fuel pressure rating. Neither one is adjustable.

[John 69 Camaro]

I'm under the impression Regulator 3584 is used on Pro-Flo 3503 & 3507 and Regulator 3597 is used on Pro-Flo 3500. Since I have an original Pro-Flo 3500, I am using Regulator 3597. Are they interchangable or do I need to stay with the 3597?

Since the replacement 3597 doesn't have a bolt going through the center as the current one I have, can I assume this is only a design change? Do you know the purpose of this bolt that is on my original 3597 Regulator?

[John 69 Camaro]

I got everything hooked up yesterday and with the key ON I got 45PSI. When I started it the pressure went to 42PSI. I disconnected the vacuum hose and the pressure went to 45 and there wasn't any evidence of fuel in the vacuum line. So it looks like the glue job worked. Thanks for the help. John