John Deere 9.0 L Diesel Engines — Bleed Air from Coolant System
Maintenance · Cooling system
For the John Deere 9.0 L Diesel Engines, from the John Deere service manual.
Applies to: John Deere 6090H engine
Before you start
- Only remove cap when cool enough to touch with bare hands; slowly loosen cap to first stop to relieve pressure before removing completely.
- If coolant level does not drop below Full Hot, there is a leak in the cooling system; engine damage may result.
Procedure
- Remove cap from top tank (de-aeration tank) of cooling system.
- Remove EGR cooler vent plug from rear of cooler.
- Fill high pressure coolant circuit at top tank.
- Begin filling coolant recovery tank (if equipped).
- When air is purged and coolant is visible coming out of the vent hole on EGR cooler, reinstall EGR cooler vent plug and tighten.
- Complete filling coolant recovery tank (if equipped) to Full Hot mark.
- Install top tank (de-aeration) cap; start engine and run at idle for 1 to 5 minutes.
- Shut off and remove top tank cap; fill high pressure circuit tank and reinstall cap.
- Start engine and warm up for 15 minutes; top off top tank until coolant loss stops.
- Shut off engine and allow to cool; observe coolant level dropped below Full Hot in recovery tank.
- Monitor coolant recovery tank for two days; refill recovery tank or top tank as required.
Specs & values
- EGR Cooler Vent Plug to Cooler 20 N·m (15 lb-ft)
Full service-parts list: John Deere 6090H engine →
Source: John Deere service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.