Exhaust / Water Mixing Elbow

Exhaust elbow was inspected and cleaned after 4 years and was in good condition.

Inspected again 2 years later. Very little coking. There was a minor rust mark on the outside at the weld and some pitting inside. After digging at the rust point, it broke through to the inside, about the size of the thickness of a match. All advice was to replace, not to try and repair it.

Elbow replaced after 6 years and 400 hours engine running time.

Tools:

• 13mm open spanner for elbow nuts on flange

• 13mm socket spanner for tube saddle

• screw driver with minus driver

• paper towels

• tub for screws/bolts

• razor scraper

• turps

• soapy water

• dremil tool

• wire brush

• exhaust elbow and gasket (metal) Type L

Procedure:

1. loosen nut on top of the engine holding the tube saddle with 13mm socket spanner, loosen forward hose clamp and remove forward engine injection hose from elbow

2. loosen exhaust hose clamp and push down clamp

3. unbolt exhaust elbow (13 mm open spanner), ease off bolts and remove nuts and washers

4. ease exhaust elbow off bolts

5. remove exhaust tube from elbow

6. clean inside exhaust elbow in soapy water and inspect for pitting, brush vigourously with wire brush

7. When dry, use dremel tool to clean around weld line. Dig any pitting to determine extent of damage

8. Clean face of gasket and elbow flange with turps and very carefully with scraper. Do not damage either surface

9. If ok, replace in reverse order as above

10. If fitting new elbow, also fit new gasket. Gasket is metal and will only fit one way. No gasket cement is required.

Have ordered the above elbow as a replacement from haileyseye on ebay at much cheaper price than Yanmar, for $US270 plus postage 30/8/14. It is 316 stainless steel and apparently twice as thick as Yanmar fabrication.

M.Cantrell 31/8/14