Hose Clamps: Standard v. Liner

There are two primary types of “open” hose clamps. The two pictured above are SAE Size 72, which we determined is the commercial equivalent of clamp 4730-00-359-9487 [4730003599487].

On the right is the standard hose clamp. On the left is what is referred to as a “liner” hose clamp. The Red Arrow points to a shield that protects the hose from extruding through the “rack” portion of the hose clamp. Liner clamps are often called “military clamps,” but in fact, the liner is designed for clamping softer materials such as silicone hoses.

This size clamp is called out to tighten the 90 degree hose used to connect to the fording stack extension 2510-01-198-0333 [2510011980333] and to the air cleaner. (See Figure 398, Item 31).

Of interest, the standard hose clamp in Size 72 worked perfectly for the fording tube application, however the “liner” clamp was too small. In fact, the liner clamp was manufactured by Breeze, a company that is a supplier of hose clamps to the military.

Upgrade/Interchange Heater Hose Clamps

As in previous posts, we have identified hose clamp sizes and their commercial interchange numbers. For the heater hoses, we have confirmed that SAE 10 is the correct size. Above are Breeze brand clamps, and Breeze has a history of manufacturing hose clamps for military use.

SAE Size 10 hose clamps installed on manifold to heater hose pipe.

Fording: Notch for Fuel Tank Vent Hose

Hose is Figure 398, Item 30. (The Corbin clamp is not on the vent tube at time of photo)

The arrow in the photo above indicates the position where the vent hose leading from the fuel tank vent line filter 2910-01-210-5872 [2910012105872] (behind the surge tank) is to be placed for clearance when the hood is closed. Note a Corbin style clamp 4730-00-954-1251 [4730009541251] needs to be placed on the hose ends both where the hose attaches to the tube and to the filter.

The callout for this hose is for an 11″ length of CPR104420-2 (replaceable with 3/8″ air brake tubing, such as Eaton Synflex®). We instead replaced this with 1/4″ SAE J30R9 hose (which we consider a modern and equal substitute for RB1450-1-4IDX1-20D).

Our reasoning for using hose instead of tubing is based on a couple factors: First, it is called out as RB1450-1-4IDx1-20D (or equivalent) to connect the fuel tank vent line to the fuel vent line filter (See Figure 18, Item 6). We are of the opinion the hose leaving the vent line filter should be the same as the hose entering the filter, and that indication of tubing may be an error in the TM. Second, use of air brake tubing essentially requires a heat gun to soften the tubing enough to slide over the tube on the stack and bead on the filter itself. Although this can be accomplished, should field repairs be necessary, it essentially requires cutting the tubing, where the hose can be easily removed by loosening the Corbin clamps.

Note: the drawing indicating the vent line hose appears to be the same as the hose entering the vent, and does not appear to be tubing. Although this may be based simply on the artist, we are of the opinion that the hose leaving the vent should be the same as the hose entering the vent.

We note the installation instructions for the DWF kit also indicates the CPR104420-2. See http://www.hummerknowledgebase.com/driving/dwf.html (at Image 3), where is specifically calls out an 11″ length. (We do, however, note this document is extremely dated, as it calls out for use of Dexron II at Image 5). Dexron II was long ago deprecated: In 1993, GM released new Dexron-III fluid (GM Spec GM6417M and later GMN10055). As noted above, we believe the J30R9 hose is made from material superior to what was available during original engineering of the HMMWV. and stand by our recommendation to instead use J30R9 hose.

Although we have no way of knowing at this time, there may have been a UV (sun) resistance issue where the engineers preferred the air brake tubing over the hose for that reason. It may well be that the CPR104420-2 tubing has a greater resistance to breakdown that the RB1450-1-4IDx1-20D hose. However, we are around 30-some years since the original design, and materials have changed. We will monitor the J30R9 hose to determine if it exhibits any undesirable weathering characteristics.

Interchange: Air Filter Hose Clamps to SAE Size

Arrows indicating locations of three hose clamps 4730-01-189-0871

Based on the call-out from the parts manual, the three hose clamps indicated below are 4730-01-189-0871 [4730011890871] or manufacturer number H68SS. Upon our research, these part numbers cross over to an SAE 68 hose clamp. Unfortunately, while size 68 clamps can be located, they are not generally commercially available. The standard (and readily available) sizes are either SAE 64 or SAE 72. We ordered both.

As it turned out (and we will post a picture later), SAE 64 is the perfect size for these three locations. We have noted that the specifications almost always call out a hose clamp considerably longer than necessary, and often leaving too much of a “tail” to grab debris, bend, and cut hands. (See photo below).

M998 Air Cleaner hose clamp showing excessive “tail” when called out part used

This hose clamp was unmodified and as received from the military. Based on what we could tell, this was a SAE 68 hose clamp.

We ordered the SAE 72 hose clamps to interchange for the clamps called out 4730-00-359-9487 [4730003599487] for use on the fording elbow 4720-01-194-5338 [4720011945338]. Although we have not yet installed these clamps, we predict they will have a considerable tail. However, those hose clamps are (for the most part) not quite as visible. On visual inspection, it appears that the SAE 68 (and possibly SAE 64) clamps may also be appropriate at that location. We will update should this information be found incorrect.

Final Update: Interchange: Armstrong Hose RB1450-1-4IDX1-20D

In several earlier posts, here and here, we discussed a suitable substitute for Armstrong Hose RB1450-1-4IDX1-20D. We stand by our opinion that 1/4″ silicone hose is appropriate for the vent hose from the front hubs to the tubing.

We received and installed the SAE J30R9 hose (fuel injection hose) for the underhood Deep Water Fording (DWF) applications of the fording valve 4820-01-192-8030 [4820011928030] to CDR valve 4820-01-192-7678 [4820011927678] and the sensor cup 2540-01-192-4502 [2540011924502] to CDR valve.

Pictures below are of the J30R9 hose utilized:

As noted in the earlier posts, this hose is rated at 100 p.s.i. operating pressure, and bursting pressure of 900 p.s.i. We feel this is more than adequate for venting purposes, and appears to be made out of more modern material that is specifically rated for diesel and bio-diesel (as well as other fuels).

SAE J30R9 hose labeled for use with Diesel and Bio Diesel

As a further note, we will be reviewing whether we also wish to replace the general fuel lines with this hose, as we noted during our review of the M998 that it was using SAE J30R7 hose. As we noted in an earlier post, we were denied sale of J30R7 hose to California ostensibly because J30R7 hose has too high of a fuel permeation rate.

Photo: Fording Valve

Arrow points to location of fording valve on firewall (located adjacent and behind fuel filter)

As we are replacing the 30-some year old hose and tubing with new, we need to access the fording valve to remove and replace the hoses. The below picture shows the hoses attached to the fording valve.

Picture of fording valve with arrows pointing at the three hoses attached to fittings.

Both the upper and the middle tubings are called out as P/N CPR104420-1, while the bottom hose is called out as P/N RB1450-1-4IDX1-20D.  As discussed in an earlier post, the CPR104420-1 can be interchanged with 1/4″ air brake tubing, such as Eaton Synflex®. Similarly, we have determined that although not a direct interchange, we could use either 1/4″ silicone hose or 1/4″ SAE J30R9 hose (fuel injection hose). For this application, even though the silicone hose has a much higher temperature rating, we had concern about abrasion on the hose so we substituted the J30R9 hose instead of the silicone. We do however, believe that the silicone hose would be more than acceptable as a substitute under most circumstances.

The parts manual shows an exploded view of the hoses and tubing that connect to the fording valve.

Excerpt from Figure 399

As shown above, the fording valve 4820-01-192-8030 [4820011928030] (Item 2) has three hoses connected to it. The lower hose goes to the lower fitting on the DWF (Deep Water Fording) CDR valve. The middle tubing goes to a line running across the cowling and tees into the vent line from the power steering pump cap. Although this is considered a special cap for DWF applications 2590-01-192-4425 [2590011924425], it is simply a standard power steering cap with a 1/8″ nipple adapter screwed into a hole in the center of the cap.

We have diagrammed the middle hose connection (Item 7) and fording valve top connection (Item 3). to view the diagram, please refer to this updated post.

Update: Interchange: Armstrong Hose RB1450-1-4IDX1-20D

In previous posts, we have indicated that we have substituted RB1450-1-41DX1-20D hose with 1/4″ silicone hose for the vent lines leading from the front hubs to the vent system.

This same hose is indicated for use on vent lines and in the fording kit. We have found that this interchanges to Eaton Weatherhead H10104.

UPDATE (12/29/2018): Apparently AC Delco 32102 (SAE J30R7) is not legal in California. We were denied sale both by Amazon and Ebay vendors.  At this time it appears its illegality is that it has too high of a fuel permeation rate relative to other hose ratings (despite the fact we are using the hose for venting, not fuel). We have ordered SAE J30R9 hose (fuel injection hose) in place of the AC Delco 32102.

J30R9 hose is still quite not identical in specification to the RB1450-1-41DX1-20D hose, as it is is rated to a maximum operating pressure of 100 p.s.i. (compared to the 350 p.s.i. of the Eaton H10104), and a burst pressure of 900 p.s.i. Regardless, for underhood and venting purposes, J30R9 hose will be superior to the J30R7 hose.

The temperature rating of J30R9 is -31°F to 275°F (intermittent to 302°F); which is superior to either the J30R7 or the H10104, although the cold temperature limit has been slightly decreased from -40 F to -37 F.

************************* older information below**************************

We have ordered AC Delco 32102 (the 25′ length of SAE J30R7 1/4″ hose) as a potentially less expensive, but just as serviceable replacement. Our concern is not heat (as silicone has considerably greater working temperature range), but more concern about potential abrasion issues.

This hose is intended for Fuel Line PCV/EEC, and is apparently repackaged Gates hose. Intended for low pressure (50 p.s.i.), this should suffice for venting purposes as well as be able to handle underhood heat. (rated -40 F to 257 F).

It is rated considerably lower than Eaton H10104, which has a pressure rating of 350 p.s.i, but a slightly lower rating of -40 F to 212 F.

A study in Steering Gear Bolts

As discussed in an earlier article, there are two 7/16-14 x 5.25 bolts 5305-01-213-4149  [5305012134149]  and one 7/16-14 x 4.00 5306-01-254-6356 [5306012546356] required to mount the steering gear to the frame. The 5.25″ length can be sourced as GM 9430761, however the 4″ bolt as MS35764-861 is not easily sourced, but 4″ long bolts are a standard length, unlike the 5 1/4″ length.

This article is about whether the length is that critical.  We do not believe so. (but read “word of caution” at end of article) For restorative purposes you may want the length to be as close as possible, or if not, to otherwise serve as a useful upgrade.

The picture below shows the clearance against the steering box when using the 4″ long bolt:

Note that the bolt extends through nearly 1/4″, and would likely have extended slightly further had we used a standard Grade 8 SAE washer instead of the “extra heavy” ones that we did. Further note that the end of the bolt can actually butt against the housing, the threads do not go above or across the top of the housing. Ensure that the end of the bolt does not butt up against the housing, which will result in a false reading with a torque wrench.

Note there isn’t a tremendous amount of clearance between the end of the bolt and the housing itself.  You can see that it was threaded into the housing so the bolt didn’t bottom out.

Ensure that whatever bolt/washer combination you use in the 4″ location that the bolt does not deadhead against the housing. (this would likely result in the upper boss of the steering gear not being drawn tight into the frame as well as causing an erroneous reading with a torque wrench.)

What about substituting longer or shorter bolts?

For the 4″ length bolt, the next shorter standard length would be 3 1/2″, and although that would at least partially engage most of the threads in the boss, we would advise against it except under emergency circumstances since this boss is the only one of the top two that even gets a bolt.

Our opinion changes slightly on the two lower 5 1/4″ length bolts.

In the picture above, you can see how far the 5 1/4″ lower bolts extend past the bosses in the steering gear. There is no doubt that a 5 1/2″ bolt might work (assuming the threaded section of the bolt is long enough and doesn’t bottom out in the boss).

Pictured above are (top bolt), the sole 5 1/4″ bolt remaining in the M1038. The middle bolt is the GM 9430761 discussed above, and the bottom bolt is one supplied by one of the “big 3″ suppliers. The bottom bolt is in fact, a 5 1/2″ length bolt. Because we had concerns that the threads would not be long enough (and bottom out in the boss) we chose to not use the 5 1/2″ bolt and acquired the proper length of 5 1/4.” It is likely that people may have erroneously replaced this bolt with the incorrect length which could potentially lead to a dangerous situation.

In our opinion, the most rearward of the lower bolts could be a 5″ long bolt without any adverse issues. As we installed it, it is nearly 1/2″ past the boss. The frontward one could also likely get by with a 5″ length bolt and still thread completely into the boss.

A word of caution, however, is that the steering is one area you don’t really want to take risks in. You limit your liability and ensure vehicle safety by using the correct fasteners, or at least the correct length of fasteners called out by the manufacturer.

Interchange: Fan Solenoid Mounting Clamp to SAE Size Hose Clamp

Both the fan control solenoid and mounting clamps had already been scavenged from the 1038.

Finding a replacement solenoid (Fig. 177, Item 5) 4810-01-192-5817 [4810011925817] was relatively simple, and just about every supplier stocks it.

It would be nice to find a cost-effective substitute, but as of yet, we have not located one that would be both cost-effective and a simple retrofit.

The clamps holding the solenoid to the body were also missing. The parts manual (Fig. 177, Item 6) does a call out for 4730-00-204-3491 [4730002043491] but fails to specify its size.

After researching the NSN and manufacturer number of C32P, we identified this clamp as a 40-64mm or (1 9/16″ to 2 1/2″) stainless gear clamp. This clamp is an SAE 32 hose clamp. We acquired a box of ten Breeze brand clamps for our application, although only one is required. In fact, it appeared during our research that Breeze or its parent company may have actually been suppliers of this clamp to the government as 4730-00-204-3491.