Can't get soap to feed into system - McCulloch FHH18A Electric Pressure Washer

In most cases this is because you have a high pressure tip, the red, white, yellow or green tip, on the wand. The detergent system will only work if you have the black, soap tip on the wand. With a pressure tip on the wand, there is too much back pressure for the syphon system to work. If you are using the soap tip, check the feed tube for the detergent for blockage, especially at the pickup filter and where it attaches to the water line.

it only will pull soap with the large hole tip or no tip very low pressure

Soap injectors are easily clogged or will not work because of design (air leaks will prevent chem from entering if chemical has to be drawn uphill) . They work with siphon action and will only work with very little pressure at the tip but good volume. If your siphon valve has the ball in place, however is missing the fine spring that holds the ball against seat (fine spring holds ball aginst intake fitting), the soap will not be sucked into stream. If ball and spring are in place, try elevating the soap container higher than the opening of the port (gravity feed may help to feed soap into system) . May be better to use an aftermarket downstream injector valve sold on ebay or many outlets. Cost about $20 but work better and are adjustable to save on soap. Search ebay for "Chemical Injector For Pressure Washers" or google "Pressure Washer Downstream Chemical Injectors" Various prices but lower price units work better than factory. Good luck

I suggest you remove the soap dispenser drawer and thoroughly clean it, ensuring that the outlet at the back of the drawer where the water and soap feed into the machine are completely clear of any soap buildup.

Before you replace the drawer, ensure that the water feed into the drawer (this is a pipe or tube above the drawer slot) is not clogged with soap.

Correct nozzle to use

Repairing chemical injector

Sounds like this is the case check your hose from soap drawer that feeds drum, may need unblocked.

The feed rollers are dirty. There are professional cleaners you can buy specifically designed to clean printer rollers but if you were to use a paper towel with a drop of soap and water it would clean off all the paper dust that has accumulated on the rollers. Use a second paper towel with just water to remove any residual soap.

1. Check any small pieces of paper, sometimes the back will come off
2. If it feeds sometimes but dog ears(bends the corner), there more likely something caught inside, use can air to blow inside lower feed rollers
3. If it does not feed or feeds and jams then take dish soap and water and apply it to a rag and clean any roller you can see make sure you let it dry before trying to print ONLY dish soap and water.
4. If this fails then there is something wrong with the feed mechanism example clutch or spring

There are 2 versions of the Hotpoint WD640, a cold fill only version, and a hot and cold fill version..
From your question, I conclude you have the hot and cold fill version, which requires a hot and cold fill supply..
I do not understand what you mean by leaking from top banch, perhaps you can clarify.

Please rate my solution.
Thankyou.

Clean the roller that feeds the paper (located at the right side inside the feeding tray).
I did it ,with a cotton pad: first impregnated with water an soap, then only with water to clean the soap and then with a dry pad. I did making the roll to roll printing a page without paper in the try and continuosly presing the cancel/resume button.