DoubleL Posted January 12, 2022 Share Posted January 12, 2022 Hey guys I worked out the part numbers for my radiator hoses today. For my 2005 Knight with 8.3L Cummins. Didn't know if they were already listed somewhere or not so here they are Bottom hose from engine to transmission cooler NAPA 7496 Dayco 70921 Bottom trans cooler to pipe going to radiator NAPA 7905 Dayco 70920 Top radiator pipe to engine NAPA 7905 Dayco 70920 Straighy piece from top and bottom pipes to radiator 2 1/4" or 57mm Straight radiator hose I used 1 ft of NAPA 637 hose and cut in half. 2 Link to comment Share on other sites More sharing options...
Gary 05 AMB DST Posted January 14, 2022 Share Posted January 14, 2022 WOW! Thanks Larry. That was always a concern of mine of a broken hose on the road. I wish I knew that two years ago when I flushed my cooling system to switch to Cummins ES Compleat, a million mile coolant. Guess I'll buy them now and keep them ready. But, it seems like every time I buy something for that purpose, I never need it. Is the Knight the Monaco version of Holiday Ramblers' Ambassador? Gary 05 AMB DST Link to comment Share on other sites More sharing options...
DoubleL Posted January 14, 2022 Author Share Posted January 14, 2022 I think it is Gary. I know they both have the same floor plans. It isn't a terrible job to change the hoses. A bit of crawling around underneath. I changed the thermostat as well while I was doing it. Link to comment Share on other sites More sharing options...
Frank McElroy Posted January 17, 2022 Share Posted January 17, 2022 On 1/12/2022 at 6:55 PM, DoubleL said: Hey guys I worked out the part numbers for my radiator hoses today. For my 2005 Knight with 8.3L Cummins. Didn't know if they were already listed somewhere or not so here they are Bottom hose from engine to transmission cooler NAPA 7496 Dayco 70921 Bottom trans cooler to pipe going to radiator NAPA 7905 Dayco 70920 Top radiator pipe to engine NAPA 7905 Dayco 70920 Straighy piece from top and bottom pipes to radiator 2 1/4" or 57mm Straight radiator hose I used 1 ft of NAPA 637 hose and cut in half. Thanks for the info - I added it to our parts list. Link to comment Share on other sites More sharing options...
DoubleL Posted January 17, 2022 Author Share Posted January 17, 2022 No Problem. I have updated filter and Belt info as well because the manual is wrong. Will post it this week. Link to comment Share on other sites More sharing options...
Gary 05 AMB DST Posted October 17, 2022 Share Posted October 17, 2022 Larry, the straight NAPA hose, 637, is listed at 2.125 ID. The other radiator hoses you listed are 2.25 ID. Should it be 666? Gary Hester 05 AMB DST Link to comment Share on other sites More sharing options...
olywrestle Posted December 21, 2022 Share Posted December 21, 2022 On 10/17/2022 at 1:59 PM, Gary 05 AMB DST said: Larry, the straight NAPA hose, 637, is listed at 2.125 ID. The other radiator hoses you listed are 2.25 ID. Should it be 666? Gary Hester 05 AMB DST Did you ever figure out if it should be 2.25 or 2.125? Going to replace everything in the next couple weeks and want to get it ordered in advance. Link to comment Share on other sites More sharing options...
olywrestle Posted January 4, 2023 Share Posted January 4, 2023 So I just did new hoses on my 2006 Ambassador. These PN's were great! And saved me a good amount of time matching things up. A couple of notes to save people some money potentially. The 2 straight pieces of 2.25 ID hose going from radiator to pipes I could only find in 3' increments. When installing PN 70921 (Engine to Transcooler) hose, you actually cut off a large segment of straight hose. Enough to do one (1) of the straight pieces mentioned above. I could have saved money if I ordered Qty 2 of 70921 (use 1 for engine to transcooler, and other for T-stat to pipe) and Qty 1 of 70920 and used the cutoff pieces from the straight hose pieces. Example as originally posted (RockAuto pricing) Qty 2 of 70920 - $12.37 each = $24.74 Qty 1 of 70921 = $24.79 Qty 1 of 76225 (3' 2.25 ID) = $31.77 Total = $81.30 Example using logic mentioned above Qty 1 of 70920 = $12.37 Qty 2 of 70921 = $49.58 Cut pieces from 70921 as your straights (6" each) Total $61.95 Couple of other notes: I ordered the C-Low Fab surge tank, it is very nice quality and bolted right up. The included nipples out of the top of the tank, were larger diameter than the original hoses. So I opted to replace those "bleeding" lines with 3/8" heater hose which meant replacing nipples on the engine block and the pipe to top of radiator. I did the all of the hoses without removing the radiator, but this meant removing the solid pipe sections which are held on by exhaust hanger U-bolts. These of course snapped off at the ends when I tried to remove them, so you would want some on hand. I did the Restore Plus Cleaner since I knew nothing of this engine and it removed A LOT of crap. It took a good 6 or 8 flushes (I lost count) to get good clear water. So plan extra time if doing a cleaner. Thermostat kit from Cummins (PN 5284903) includes both O-rings, so no need to order extras. Needed plenty of zip ties to re-attach wiring looms to hoses. Save old hoses to eliminate rub points as required. Link to comment Share on other sites More sharing options...
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