Graco 15E813 Jam Nut

Graco 15E813 Jam Nut is a small yet essential part that locks the siphon hose securely to the fluid pump, preventing leaks and ensuring reliable operation across multiple Graco sprayers.

Replaces older part number 15B434
Used in FinishPro, ST Max, Ultra, Ultra Max II, and GMAX models
Durable and easy to install for long-term performance

$5.25

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Description

Overview & Key Details for Graco 15E813 Jam Nut

Graco 15E813 Jam Nut secures the siphon (suction) hose connection to the sprayer’s fluid pump. It replaces/was formerly referenced as 15B434 on some diagrams. Always confirm against your unit’s parts list before ordering.

Compatible Machines

FinishPro 290 (256842)
FinishPro 390 (249690)
FinishPro 395 (249691)
190 ES (261825)
290 ES (261830)
ST Max 490 (253013)
ST Max 495 (249978)
ST Max 595 (249930)
GMAX 3400 Hi-Boy (248664)
GMAX 3400 Lo-Boy (248666)
Ultra 395 (233962)
Ultra 495 (233968)
Ultra 595 (234435)
Ultra Max II 490 (249914)
Ultra Max II 495 (249917)
Ultra Max II 595 (249919)
RentalPro 210 (262906)
Electric Airless 190LTS (257075)
GMAX 340 (per Graco/retailer listings)

Specifications

Part Number	15E813
Also Known As	15B434 (former reference on some diagrams)
Function	Locks/retains the siphon (suction) hose connection to the fluid pump inlet.
Usage	Common across multiple FinishPro, ST Max, Ultra, Ultra Max II, GMAX and Rental series units.
UPC	633955088719
What’s in the Box	1 × Graco 15E813 Jam Nut
Fitment Tip	Verify against your sprayer’s parts list or diagram before purchase.

Frequently Asked Questions

It secures the suction/siphon hose at the pump inlet to prevent loosening or leaks during operation.

Yes - some diagrams reference the earlier number 15B434; the current replacement jam nut is 15E813.

Match your exact model/variant (e.g., “Ultra Max II 495 Hi-Boy 249917”) against its parts list. This nut is widely used across the models listed above.

Hand-start threads to avoid cross-threading, snug the jam nut to secure the hose, and check for leaks after priming. Do not overtighten; consult your unit’s manual for torque guidance.