how to repair valve seats

How to Repair a Toilet Flush Valve Seat

1. Turn Off the Water and Flush. Turn off the water and flush the toilet. ...
2. Disconnect the Chain and Flapper. Disconnect the flapper chain and unhook the flapper from the overflow tube. ...
3. Wipe the Valve Opening. ...
4. Check the Sealant Ring. ...
5. Take Off the Old Seal. ...
6. Wipe and Dry the Bottom. ...
7. Install the Ring. ...
8. Replace the Flapper. ...
9. Finish the Flapper Seat Replacement. ...

Full Answer

How do you replace valve seats?

To ensure proper seating of the valve, the valve seat must be:

• Correct width
• Correct location on the valve face
• Concentric with the guide (less than .002? runout).

Is it costly to replace a broken valve seat?

To remove and replace check valve seats reliably and in a cost-effective manner, the valve repair vendor must utilize custom tooling, procedures and techniques. Utilizing this special tooling, craft personnel have performed numerous successful seat replacements on check valves, ranging in size from 12-inch NPS to 50-inch NPS.

How to replace valve seats?

• The Switch To Aluminum Cylinder Heads. The cylinder heads today are mostly aluminum. ...
• Upgraded Materials For Diesels With Higher Operating Temperatures. These upgraded materials are often nickel or cobalt based and come with a corresponding increase in cost.
• Valve Seats Cutting Techniques. ...

How to clean valve seats?

freshening valve seats ?

1. Lapping compound has it's place to use. There are many different types and varieties. ...
2. Lapping compound IS NOT a replacement for a valve job.
3. There is no replacement for a real valve job.

How do you fix a worn valve seat?

10:0511:26How To Grind/Seat Valves and Replace Seals - YouTubeYouTubeStart of suggested clipEnd of suggested clipPull it right off. And that's what it looks like in those two stews two-sided keepers are rightMorePull it right off. And that's what it looks like in those two stews two-sided keepers are right there they won't let go well that's it that's how you seat your valves. And replace the seals.

How do you fix a leaky valve seat?

2:213:49Checking valves for leaks - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo you will either need to grind the valve a little bit or grin the seat a little bit or maybe evenMoreSo you will either need to grind the valve a little bit or grin the seat a little bit or maybe even just laugh about I have to try a few things to see what we can do to make that valve seal.

How do you resurface a valve seat?

0:424:36grinding “valve seats” WITHOUT expensive tools - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd I'll cut off little strips here and we'll cut off a few small pieces that'll fit the contour.MoreAnd I'll cut off little strips here and we'll cut off a few small pieces that'll fit the contour. Now I'm just gonna add just a drop of super glue onto. The back of the sandpaper.

How much does it cost to replace valve seats?

The most expensive part of a valve job is the labor. It can take up to 7 hours to complete the job correctly, meaning each piece is resurfaced, the seats are drilled out, and the valves reseated. Labor can cost between $70 and $150 per hour, meaning you could expect an average of $770 for labor alone.

Can valve seats be repaired?

Replacing valve seats is one of the basic jobs that is often necessary when rebuilding aluminum or cast iron heads with cracked, damaged or badly worn seats. But there is a lot more to replacing a valve seat than prying out the old one and driving in a new one.

Can you weld a valve seat?

A fabricated seat can be installed in the valve body and seal welded in lieu of a complete weld repair solution for the seating surface.

How do you grind valve seats at home?

0:149:52Cutting and Grinding Valve Seats - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd we're gonna be showing you how to grind some valve seats today first step is to get yourMoreAnd we're gonna be showing you how to grind some valve seats today first step is to get your cylinder head set up on the machine nice and tight and get it centered.

Can you lap valves with a drill?

Don't take short cuts ... that's what got you to need to lap the valves in the first place. The drill won't spin it in more than one direction. You won't get much force on the face of the valve this way either. I prefer to do them by hand as you can get a good feel for how well the job is going.

How do you grind valves by hand?

3:3811:36How-To: Lap Valves (by hand and drill method explained) - YouTubeYouTubeStart of suggested clipEnd of suggested clipClean okay and what you're going to take is some valve grinding compound. And just put a couple dabsMoreClean okay and what you're going to take is some valve grinding compound. And just put a couple dabs. On. So i just like to do like. Three three dabs just like that. Take it and put your valve. In.

What causes valve seat damage?

Possible causes include an incorrectly set valve clearance − or the valve seat insert or valve guide were not remachined centrically. An excessively large or small valve guide clearance can also have fatal consequences.

Can I do my own valve job?

0:105:14DIY Backyard Valve Job - YouTubeYouTubeStart of suggested clipEnd of suggested clipAway the exhaust to see these hands these almost price for heads they came at hardened season toMoreAway the exhaust to see these hands these almost price for heads they came at hardened season to begin with. But even with hard to seats they still will. And they can always be freshened.

How do I know if my valve seats are bad?

Conducting a Cold Engine Test. One of the best ways to tell if you have a faulty valve seal is to conduct a cold engine test. ... Increased Smoke Levels. Depending on the machines and equipment you use, smoke is often a common form of exhaust. ... More Oil Consumption. ... Engine Idling. ... Compromised Acceleration Power. ... Engine Misfiring.

Why does my valve seat run out?

Valve Seat Runout. Excessive runout will eventually break the valve head off at the underhead radius. This is due to the flexing that occurs every time the valve; opens and closes against the seat. The most common causes of excessive runout are a loose fitting pilot; and the condition of the machine spindle bearings.

What is OEM seat?

The growth in the (OEM) seat market has led to the widespread use of powder metallurgy. Allowing (OEM)s to produce inserts in large volumes. These valve seats are engine specific; and can almost exactly replicate the heat transfer characteristics of the parent metal.

What is the intake valve on a premium engine made of?

The intake valve in the premium engine is made from tribaloy and; must be run with a tribaloy seat insert. Diesel Cylinder Head. These alloys have hardness values around 50 to 55 HRC and maintain higher hardness at elevated operating temperatures. Tribaloy is abrasion resistant.

Why is seat width important?

The seat width is important because about 70% of heat transferred from a valve; goes out the seat contact area. The old rule of thumb used to be to try to maintain a seat width of about .070″. Today’s engines, have valves that are so thin it is impossible to locate a seat that wide on the valve.

What is the switch to aluminum cylinder heads?

The Switch To Aluminum Cylinder Heads. The cylinder heads today are mostly aluminum. With the exception of diesels and truck engines. These heads have inserts already fitted at the factory; this has contributed to the growth in the seat insert market at the (OEM) level.

What to do if your flush valve is leaking?

If you aren't sure if the flush valve is leaking, put food coloring in the tank. The valve is leaking if the bowl water turns that color. Chris Deziel has a bachelor's degree in physics and a master's degree in humanities.

What happens when the toilet fill valve wears out?

When either the flapper or the valve seat wears out, water seeps from the tank to the bowl, and the fill valve either cycles on and off or runs continuously. That's not only annoying, but it wastes water.

How to empty a toilet tank?

1. Turn off the water and flush the toilet. Hold the handle down until no more water goes out of the tank, then sponge what's left into the bowl to completely empty the tank.

Why replace valve seat?

Another reason to replace a seat is if a valve has broken because the seat is not concentric with the guide. Misalignment between the seat and guide causes the valve stem to flex every time the valve closes.

What happens if a valve seat is cracked?

If a valve seat is damaged, cracked, loose, receded or too badly worn to be recut or reground, it can cause a variety of problems: loss of compression, valve burning, valve failure, valvetrain wear and breakage, even head and valve damage if the seat comes loose.

How to check concentricity of seat?

The best way to check concentricity is with a runout gauge. Pulling vacuum on the valve port with the valve in place is another method for checking the mating of the seat and valve. But the ability to hold vacuum is no guarantee of concentricity. Both methods should be used to check the quality of your work.

What is the interference between valve seat insert and head?

The recommended amount of interference between the valve seat insert and head may vary depending on the size of the insert, the type of insert (alloy or powder metal) and type of head (cast iron or aluminum). The best advice is to use the amount of interference recommended by the OEM engine manufacturer.

Why replace seats in late model heads?

Advertisement. Emert said another reason for replacing seats in some late model heads is because the OEM powder metal seats become too hard to machine. Many late model gasoline engines with aluminum heads from Ford, GM, Chrysler and many imports are factory-equipped with sintered powder metal seats.

What is the most popular aftermarket seat material?

Tom Tucker of Tucker Valve Seat, says 440 stainless steel seats or Silicone XB (an iron seat with 18 percent chrome) are the most popular aftermarket seat materials today. But he also stressed the importance of choosing a seat that’s designed for a specific application. Advertisement.

Why does my seat come loose?

Too much interference runs the risk of cracking the head while too little interference increases the risk of the seat coming loose or falling out. One of the leading causes of seats coming loose, however, is not the amount of interference between the seat and head but elevated operating temperatures.

Why pull intake and exhaust manifold back?

When a valve job is to be performed, it may be common procedure for the technician to just pull the intake and exhaust manifolds back to provide just enough room to get the cylinder head off of the engine. Doing so does not allow ample ability to clean either manifold.

Is a Ford plenum easy to take apart?

Doing so will offer optimum engine performance for this engine.’. On the Ford plenums, they’re easy to take apart, clean and put back together. The Chrysler Hemi’s are exactly the opposite. They are 2 pieces that are glued, for lack of a better word, together.

What does a valve seat do?

A valve seat must do several things. It must support and seal the valve when the valve closes, it must cool the valve, and it must resist wear and recession. Consequently, a performance valve seat material should provide a certain amount of dampening to help cushion the valve when it closes at high rpm.

What happens if the valve seat insert is loose?

If the valve seat insert shows evidence of being loose or doesn’t have adequate interference ; if there is evidence of corrosion on the cylinder head around the outside diameter of the valve seat; or if there is evidence that the seat has any cracking, burning, pitting or fissures, the seats must be replaced.

How many degrees of tilt can a seat and guide machine accommodate?

Once you’ve set the powerhead angle you can go up and down the line with the same tilt angle for each valve seat. Some machines can accommodate up to 15 degrees of rotating tilt.

What happens when a valve opens?

Every time the valve opens, tiny chunks of metal are torn away and blown out the exhaust. Over time, the seat is gradually eaten away and the valve slowly sinks deeper and deeper into the head. Eventually the lash in the valvetrain closes up and prevents the valve from seating. This causes the valve to overheat and burn.

How are powder metal seats made?

Powder metal seats, by comparison, are made by mixing together various dry metal powders such as iron, tungsten carbide, molybdenum, chromium, vanadium, nickel, manganese, silicon, copper, etc.), pressing the mixed powders into a die, then subjecting the die to high heat and pressure (a process called “sintering”).

Why do my seats crack?

Seats can crack from thermal stress (engine overheating usually), thermal shock (a sudden and rapid change in operating temperature) or mechanical stress (detonation, excessive valve lash that results in severe pounding, etc.). A small amount of valve recession results from normal high mileage wear, but it can also occur when unleaded gasoline ...

Do valve seats need to be replaced?

Advertisement. Valve seat replacement is required if the cylinder head was warped and needed to be straightened before resurfacing. Similarly, if an aluminum head was cleaned by heating, the se ats will need to be replaced.

What happens if a car seat fails?

When this seat failed, the engine, if shut off immediately, still would have turned over a number of revolutions sucking all the “shrapnel” up into the intake plenum. By not cleaning it, more than likely those pieces will be sucked back down into the engine and you might wind up doing it all again, ughhh.

How to check if piston is seized?

To check whether the ring (s) are seized, with to piston at the top of the bore, try and move the piston from front to back. It won’t move much, a few thousands of an inch. If it moves, you’re OK. The other thing you should do is run the piston down to the bottom of the bore and check for cylinder wall damage.