Chevy P30 454 (7.4L) Fan Belts And Hoses

[DaveVA78Chieftain]

Fan Belts





Power Steering Pump Mounting on P30 454



A - Insert 1/2" breaker bar (or 1/2" rachet) in square slot to apply pressure to tighten PS belt.  The adjustment bolt is hidden behind the PS Pulley and fan blade in this picture.
B - AC Compressor adjustment bolt
C. AIR pump adjustment bolt
D. Alternator adjustment bolt

Note: Many P30 chassis' use a Hydroboost braking system.  The Hydroboost unit uses the PS pump as a pressure source therfore, loss of the PS belt will affect both steering and brakes.

Crank, Water Pump, Alternator Belt

Year	Description	Part Number	Belt Tension
1979 - 1985		GM: 9433752   NAPA:  15495 or 257495   Autozone: 15495 (Duralast)	Used: 75 +/- 5lbs   New: 125 +/- 5lbs
1990	Serpentine   52.75 inches   (1340 mm)	GM: 10085787   NAPA: 6K525 or 25060525HD      Autozone: 525K6 (Duralast)	Used: 75 +/- 5lbs   New: 125 +/- 5lbs

Crank, Water Pump, Alternator, Air Pump Belt

Year	Description	Part Number	Belt Tension
1985 1/2 - 1989	Poly V, 6 Rib   55.98 inches   (1422.0 mm)	GM: 14087540   NAPA: 6K560 or 25060560 or   25060560HD   Autozone: 560K6 or 5060560      or 560K6	Used: 75 +/- 5lbs   New: 125 +/- 5lbs

Crank to Power Steering Pump Belt

Year	Description	Part Number	Belt Tension
1979 - 1985	Without A/C	GM: 9433745   NAPA: 15460 or 257460   Autozone: 15460 (Duralast)	Used: 75 +/- 5lbs   New: 125 +/- 5lbs
1985 1/2 - 1990	Without A/C   .47 inch x   45.5 inches	GM: 10034695   NAPA: 15455 or 257455   Autozone: 15455	Used: 75 +/- 5lbs   New: 125 +/- 5lbs
1985 1/2 - 1990	With A/C,   Hi Ride   3/8 inch x   41 inches   GM Code: XL	GM: 9433735   NAPA: 15410 or 257410   Autozone: 15410 (Duralast)	Used: 75 +/- 5lbs   New: 125 +/- 5lbs

Crank, Power Steering Pump, A/C Compressor, Water Pump Belt

Year	Description	Part Number	Belt Tension
1985 1/2 - 1990	Hi Ride   3/8 inch x   60.5 inches   GM Code: GA	GM: 14033869   NAPA: 15603 or 257603   Autozone: 15603 (Duralast)	Used: 90 +/- 5lbs   New: 135 +/- 5lbs

Power Steering Pump to 2nd AIR Pump Belt (NA5 Code chassis only)

Year	Description	Part Number	Belt Tension
1985 1/2 - 1990	With and   Without A/C   All Federal,   Hi Ride   .47 inch x   45.00 inches   GM Code: CNA	GM: 10034695   NAPA: 15455 or 257455   Autozone: 15455 (Duralast)	Used: 75 +/- 5lbs   New: 125 +/- 5lbs

Hoses

Upper Radiator Hose

Year	Description	Part Number
1973 - 1981	Vertical Radiator   350 Engine	GM: 6259952   NAPA: 7575   Autozone: E70935 (Dayco)
1973 - 1981	Vertical Radiator   454 Engine	GM: 6259953   NAPA: 7537   Autozone: B70846 (Dayco)
1982	Horizontal Radiator   454 Engine   (Varies by Model &      option)	GM: 14049401   NAPA: 8153   Autozone: B70846 (Dayco)   GM: 15599363   NAPA: 8232   Autozone: E71429 (Dayco)
1983	Horizontal Radiator   454 Engine	GM: 15595586   NAPA: 7537   Autozone: B70846 (Dayco)
1984 (H4D)	Horizontal Radiator   454 Engine	GM: 14049401   NAPA: 8153   Autozone: B70846 (Dayco)
1985 - 1989 (H5D)	Horizontal Radiator   454 Engine	GM: 15599363   NAPA: 8232   Autozone: E71429 (Dayco)
1990 - 1994 (H5D)	Horizontal Radiator   454 Engine	GM: 15638164   NAPA: 8153   Autozone: B70846 (Dayco)

Lower Radiator Hose

Year	Description	Part Number
1973 - 1981	Vertical Radiator   350 & 454 Engine	GM: 343414   NAPA: 7581   Autozone: E70735 (Dayco)
1982	Horizontal Radiator   350 Engine	GM: 343414   NAPA: 7581   Autozone: E70735 (Dayco)
1982 - 1984	Horizontal Radiator   454 Engine	GM: 14049500   NAPA: 8154   Autozone: E71430 (Dayco)
1985 - 1994	Horizontal Radiator   454 Engine   (Varies by Model & option)	GM: 14049500   NAPA: 8154   Autozone: E71430 (Dayco)   GM: 15595587   NAPA: 7537   Autozone: B70846 (Dayco)   GM: 14042372   NAPA: 7537   Autozone: B70846 (Dayco)

[Oz]

And it would best to be a separate topic - > Chevy 454 (7.4L) Fan belts & hoses AIR removed   

[bnlfan]

I am having a hard time finding the ps to hydroboost belt.  It is 41 inches but very thin v belt.  Any one know the part number?  It is the belt on the rear of the pully.

[Rickf1985]

The power steering IS the hydroboost? Are you talking about the belt that goes around the AC? The one on the back of the pulley if I remember correctly goes to the A.I.R. Pump on top center of the engine.
This information is the very first post in this thread on four posts above yours!

1985 1/2 - 1990

With A/C,   Hi Ride   3/8 inch x   41 inches   GM Code: XL

GM: 9433735   NAPA: 15410 or 257410   Autozone: 15410 (Duralast)

Used: 75 +/- 5lbs   New: 125 +/- 5lbs

[bnlfan]

Perhaps it is not a stand alone hydroboost pump.  But there is a belt not found in the list, .  I got all the belts and then some, listed on this thread.  This belt is barely as big around as a pencil.  It is a v belt with no teeth.  Laying under the motor,it is on the back half of the power steering pulley. It is at the very bottom of the motor.  If you are on your back facing up, head by the transmission, the dual pulley is on the left and it goes to a pulley next to it.


None of the belts listed that the autoparts people cross matched are anywhere close.   The belt measures right at 41 inches and about 6 mm wide.

[bnlfan]

Autopart store measured it and said a gates 7409 v belt should work.  I ordered one but it has teeth.




I just realized that the belt on there may be the wrong one.  I bought this rev used.  I will let you all know and post images.  I hate having to learn the hard way.

[DaveVA78Chieftain]

I think it should be the 7410 which is what gates says it should be.
7409 is .265" (6mm) wide x 41.34" long
7410 is .41" (10mm) wide x 41.57" long

[Rickf1985]

The ribbed belts were designed to run cooler and therefore last longer. They are no different in use than the solid ones.

[bnlfan]

Ok.  Got the exact belt I needed 7409 is exactly like what came off.

[CapnDirk]

Was what came off the right one?   

[bnlfan]

I Don't really know.  I can not find out from anyone.  I know this one worked.  So I guess so.

[Rickf1985]

I Don't really know.  I can not find out from anyone.  I know this one worked.  So I guess so.

The numbers we gave you are the correct ones for replacement. Since it is narrower and shorter it will ride lower in the groove and therefor it will not have to be adjusted in for the shorter belt. It will not last as long because it will hit the bottom of the groove and start to slip but it will work for a while. The correct belt should sit flush with the top edge of the pulley when tightened.

[bnlfan]

I have all the belts listed.  None of them are narrow enough.  Regardless, I am climbing under Saturday and checking them all for fit.

[CapnDirk]

Bnlfan.  Do both/all the pulleys have the same width grove?  What I'm getting at is if someone replaced a component (compressor, PS pump, alternator) from another application and you fighting someone elses mistake.

[udidwht]

I have a 94 Fleetwood with a P30 chassis 454 TBI w/4L80E trans and just had a serpentine belt break on it that had less than 9,000 miles on the belt. Belt used was a Gates Micro V K060525. According to Oreilly's computer it shows it as 'Except motorhome'....what in the world!


Looking on Rockauto they also list the same Gates belt K060525 as 'Excluding motorhome'. But if you click on the belt and look at the alternate OEM numbers GM: 10085787 is listed. what in the world!

They (Rockauto & Oreilly) also list a Gates K060525HD (heavy duty) as 'Exclude motorhome. what in the world! Is a motorhome not heavy duty? LOL!

The vin on my RV is 1GBJP37N4R3314754

I replaced all the belts ~ 3 years ago. RV has no air pump.

[MotorPro]

I wouldn't worry about the "except motorhomes " . If it fits that's fine. The question is why did a 9000 mile break? Check every pulley, pump and alternator to make sure they turn freely

[udidwht]

I wouldn't worry about the "except motorhomes " . If it fits that's fine. The question is why did a 9000 mile break? Check every pulley, pump and alternator to make sure they turn freely

I noticed a week or so before the break some small damage on the outer edge of the belt. Looked like a small bite. Thinking back I had the rear bearings on the alternator fall out and the shaft seized just as I was pulling into my camp spot for the night (quite literally). Shutdown real quick but I'm inclined to believe now it compromised the belt somewhat enough to greatly shorten its overall life.


That incident was about 7 months or so after replacing all the belts in Jan. 2016. Oodometer was at 48,881 and I just crossed over 57,XXX

[78BraveGuy]

I'm planning on flushing the coolant system on my 78 Itasca P30 w/454.  I am going to replace the hoses also at this time.  I am wondering why the hose part numbers listed above don't jive with Rock Auto or Napa's websites when I select P30 chassis?  Is there a difference in radiator hoses for motorhomes vs other P30 chassis?

[Froggy1936]

If you

still have the old belt i would examine it very closely for rodent bites, The nasty little culprits will eat anything !  Frank

[Rickf1985]

The lower hoses are usually the same but the upper hoses can be different depending on how the radiator is mounted in the chassis and where the fill is. The motorhome chassis is different from the standard P30 in a lot of ways. A standard P30 is a Bread wagon, think Stroehmann bread delivery truck. Or a newspaper delivery truck. You get the idea, that was the main use of the P30 chassis.

[Baseballride351]

Is it possible to replace the belts without having to remove the radiator?

[udidwht]

Is it possible to replace the belts without having to remove the radiator?

Yes, I was able to do it on mine. It will require you to crawl underneath as well. They go on in order of power steering belts first then serpantine last.

[WVRV]

If the AIR system has been deleted, is it safe to just cut off belt D from image #2?

[Rickf1985]

Yes, as long as it is the belt that ONLY goes from the power steering to the air pump. Just be aware that doing so may change the tension of the other belt on the power steering pump and it may need to be tightened. Or loosened.

[78BraveGuy]

I took the old hoses off yesterday and they are the original GM hoses.  Part # GM 6259953 for the upper hose and Part # GM 343413 for the lower hose.  I went to Autozone and those part numbers BOTH cross reference to B70846, which is a short by-pass hose that is nothing like either of the original hoses.  Napa crosses to the same short by-pass hose.  I did some research on the internet and I get the same results.  The partsman at Autozone tried looking up a 1978 P30 and it did give him the option for "Motorhome", but when he selected that and searched for radiator hoses, it said none available.  When he selected "non-motorhome", it gave us hoses that were totally different as well (probably for stepvans).  I'm at a loss for what do to.  I thought about getting flex hoses, but the way the top hose snakes around things, I'm worried a flex hose would either kink or rub or both.  Has anyone else tried to get radiator hoses for a late 70's P30 motorhome lately?