More on 454 L 29 Engine

[trop-a-cal]

Good news this morning, as with startup the valve noise is gone. The GM advisor said if they were clacking due to the head gasket allowing in the 50-50 water antifreeze, they were then corroded and would quiet down with head repaired and no more antifreeze being drawn into the cylinders and the oil and then entire engine. So the engine purred this morning from initial start only about two hours of running with the new oil. Still have idle fading and some noise when as oil pressure drops, but back to good idle and quiet. Brakes still sticking peddle down, so that needs new fluid and possible new master, but those "it's the crank shaft and engine is shot" guys can take a long walk of a short pier. It's back in storage for now so I can find an honest mechanic to finish the repair.

[trop-a-cal]

Good idea as air probably is not present as peddle is stiff at top and only a slight air release sound is heard. The system is 4 wheel disc ABS with drum tag axle. Thanks for the pricing and advise.

[falconbrother]

I had a funky brake pedal when I bought my MH. I just replaced the master cylinder myself with a "rebuilt" unit. After the core exchange it cost me a whopping $27.00 bucks. The mastercylinder is located under the driver's seat on my P-30. It's a pain to get to and required me breaking out the air wratchet to get it apart and back together. But, it works great now. I change my fluid out every spring when I change out all the fluids.

BTW, there is a list of brake master cylinders for a P-30. NAPA never could find the right one for me. So, I skipped over to Advance Auto Parts and they got it right the first time, in stock, re-built, works perfectly. So, should you need one, take a real good look at the one on your chassis to save the back and forth driving (assuming you would change it out yourself).

[Sprig]

trop-a-cal wrote:
IT's going in for the brake fluid flush and check of idle. Brake fluid job will be around $150. More if it does not solve problem after driving it with new fluid...

Just a warning... NEW FLUID should be EXPECTED to show where the other problems are; in other words "more money".

If you have a solid pedal on the downstroke, you don't have air in the system.

If the pedal does not return, and it is a cross system, then both sides of the system are not being allowed to return.

So, what brakes does your coach have? I did not look at your profile.

If you hit the go pedal just before releasing the stop pedal, can you "feel" a tendency for the coach to rise or dive?

I'd attempt to find the problem FIRST, then spend the money for new fluid on the side that is still working right. Otherwise, you are going to end up spending the 140 twice.

[trop-a-cal]

IT's going in for the brake fluid flush and check of idle. Brake fluid job will be around $150. More if it does not solve problem after driving it with new fluid. If it's the fluid being so contaminated and causing the master piston to stick in the cylinder then clean may free it up. Next stop after that is done is back to Dave's RV Roof in Green Cove, Florida,(just west of Jacksonville on route 17), as it's Dow sprayed on roof has a spot to spray which is covered by the 20 year 100% roof warrantee. Then April it's heading to Kinderhook, NY for the Summer. With all mechanical things in order then the interior updating will start with new wide screen TV's and perhaps new carpet. This unit is now 18 years old and has 45K on it. This engine and transmission should last until 350K so many years and miles ahead.

[enblethen]

IAC valveOn the left side of the throttle body base is a "Idle Air control (IAC)valve".
I had your idle problem. I removed the valve and sprayed carb cleaner down into the manifold through the opening. I used the carb cleaner on the valve. It corrected the fast idle issue after engine warmed up.

[trop-a-cal]

Work was done to linkage last year and it acted up 500 miles from repair shop, when I got off interstate and went to local roads for fuel and food It recovered again with interstate driving, as the road vibration perhaps loosened the stuck part, which probably in the internal piston sleeve and spring in the master cylinder. That would continue to happen if the brake fluid is contaminated with particles and water, which occurs during overheating of brake fluid due to age and hung up brakes. The repair garage was advised by me to drain the brake fluid, but I did not check it and so that will be done soon. As to the low and idle, I yet to find what is causing that, but since it idles fine when cold, there may be a wire on backwards from the removal of the intake when the head was removed. Some times the wires connect at 180 degrees from proper settling.

[kcny]

Last year I had a sticky brake pedal too - mechanic looked the brake system over and it ended that the pedal and linkage just needed to be lubed.

[enblethen]

Thanks for the updates!