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Silicone Rubber Blue Coolant Hose, 1.64 Inch OD, 1.25 Inch ID, 36 Inch Long

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Description & Features

Designed for high-performance applications, this coolant hose offers exceptional durability and performance. Constructed from 4-ply silicone and reinforced with polyester fabric, it meets or exceeds the requirements of SAE J20 R1 Class A, TMC RP303B Class 1 Grade 1, and most OEM truck manufacturers' specifications.

With a burst pressure of 500 psi and dimensions of 1.64 inches OD and 1.25 inches ID, this 36-inch long hose is engineered to withstand extreme conditions. Its continuous operating temperature ranges from -65deg;F to 350deg;F, ensuring reliable performance across various temperature ranges.

The FLEXFAB Silicone Rubber Blue Coolant Hose is a robust solution for demanding industrial applications, suitable for use in refrigeration, air conditioning, and engine and air brake systems.

MPN: 5581-125

Supplier Part Number: 5581-125

Specifications

Burst Pressure
500
Brand
Flexfab
Brand
Flexfab
Pack Size
36.00
UOM
LN3
Hose I.D.
1.25
Hose O.D.
1.64
Length
36
Supplier Part Number
5581-125
Alternate Part Numbers
Alternate Part Number 5581-125, Alternate Part Number C1KG98, Alternate Part Number MI-08749330, Alternate Part Number MINO-01591X98009
Product Weight
2.73 lbs

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Product Questions & Answers (4)

Question by: Dwight L on Jul 9, 2025, 5:12 PM
got a 1-1/4 inch coolant line i’m replacing, is this hose actually 1.25 ID and what’s the outside size?
Answer by: Customer Support on Jul 10, 2025, 6:14 PM
The inside diameter is 1.25 inch and the outside diameter is 1.64 inch, with a 36 inch overall length.
Question by: Travis S on Sep 29, 2025, 5:54 PM
got a straight section to replace, do the measurements on this hose mean 1.25 on the inside and 1.64 on the outside?
Answer by: Customer Support on Oct 1, 2025, 8:46 AM
The ID is 1.25 inches and the OD is 1.64 inches, and the hose comes in a 36 inch length. It is a 4 ply silicone coolant hose with polyester fabric reinforcement.
Question by: Joyce S on Apr 6, 2025, 8:16 PM
What kind of temperatures can this hose handle?
Answer by: Customer Support on Apr 8, 2025, 6:34 AM
Continuous operating temperatures for this hose range from -65°F to 350°F.
Question by: Hubert F on Oct 8, 2025, 6:25 PM
runs from -65 up to 350 degrees -- that temperature range cover most heavy truck cooling systems pretty well?
Answer by: Customer Support on Oct 10, 2025, 6:37 AM
For typical over-the-road and vocational truck applications, that range covers just about everything you'd run into. Most engine coolant systems operate well within those bounds, and the 4-ply silicone construction with polyester fabric reinforcement helps it hold up at both the low and high ends of that span without getting brittle or soft. Cold-start conditions in harsh winters and high-load summer temps are both well within what this hose is rated to handle continuously.