Collection: Dolly Pump Kits
Dolly Pump Kits
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Dolly Kit Gp Kit 123 C...
Regular price $54.13Regular priceper
Dolly Pump Kits
The name throws people off, so here is the straight answer. Dolly pump kits are the rebuild kits for the AR, CAT, and General Pump heads found on cart and dolly style pressure washers. Valves, packings, water seals, and ceramic plungers, matched by pump model. Read the data plate on your pump, then call 301-519-9274 and we will pull the right kit number.
Match the Dolly Pump Kit to the Symptom
A worn pump tells you what it needs. You just have to listen to the right complaint. Three kit types cover almost every rebuild, and each fixes a different failure.
Valve kits: surging and pressure that will not hold
Check valves are spring-loaded discs that keep water moving one direction through the head. When debris chews them up, the machine surges, pressure climbs and falls on its own, and the pump sounds rougher than it should. Valve kits like the AR 1864 cover the XM, XMA, XMV, XT, XTA, and XTV series in one bag. CAT valve kits work the same way with one catch: a 3CP or 310 series pump needs two kits to service every valve, so order in pairs.
Packing and water seal kits: slow pressure loss and drips
Packings are the stacked seals that ride on each plunger. They wear gradually, so the machine loses a few hundred PSI over weeks instead of failing all at once. Water dripping from the weep holes under the manifold is the other giveaway. Measure or look up your plunger size before ordering, because AR alone uses 15mm, 18mm, 20mm, and 22mm packings across the XT, XR, XMV, and XW families. The kit number on the bag means nothing if the millimeters are wrong.
Ceramic plunger sets: the fix behind the fix
If you install fresh packings and the pump still drips a week later, pull the head again and run a fingernail across each plunger. A scored or cracked ceramic plunger will destroy new packings in days. Plunger sets come three to a box and turn a failed reseal into a permanent repair.
Kit Lookup by Pump
| Kit | Fixes | Fits | Price |
|---|---|---|---|
| AR 2864 Check Valves | Surging, rough running | AR RK, RKA | $16.99 |
| AR 1864 Check Valve Kit | Surging, pressure swings | AR XM, XMA, XMV, XT series | $22.99 |
| AR 2741 Water Seals | Slow pressure loss, drips | AR XMV | $35.99 |
| AR 1828 Valves and O-Rings | Surging, internal bypass | AR 1828 applications | $37.70 |
| AR 2520 Packing Kit 15mm | Slow pressure loss | AR XTA, XTV | $46.99 |
| AR 2739 Ceramic Plungers (3) | Repeat seal failures | AR triplex models | $48.99 |
| AR 2628 Ceramic Pistons (3) | Scored plungers | AR XT, XTA, XTV | $53.99 |
| GP Kit 172 Packing Seal 22mm | Drips, pressure fade | General Pump TSF | $56.04 |
| AR 2783 Packing 22mm | Drips, pressure fade | AR XW, XWA | $63.99 |
| CAT 33062 Valve Kit 3CP | Surging (order 2 per pump) | CAT 3CP | $34.99 |
| CAT 30623 Seal Kit | Drips, oil weep | CAT 30, 31, 34, 35, 310, 340, 350 | $87.99 |
These are eleven of the 50-plus kits in this collection. If your model is not listed, we can cross-reference it from the pump data plate in a minute.
From the Field
Before you order any kit, rule out the cheap stuff. A worn nozzle mimics worn packings, and a $12 nozzle beats a teardown. Chemical injector o-rings cause more mystery pressure loss than pumps do. Once you are sure it is the pump, open it once and fix it once: if the head is coming off anyway, the smart move is valves and packings together, because the second teardown costs you a job day. Two more counter lessons. Lube every o-ring before assembly or you will cut it on install. And never grip a ceramic plunger with pliers, one hairline crack and your new packings are already dying.
Related Collections
- AR pump parts
- CAT pump parts
- General Pump parts
- Comet pump parts
- Packing extraction tools
- Pressure washer repair parts
- Pump oil
- Replacement pumps
- Unloader valves
Rather have us eyeball the worn parts? Bring the pump to our Gaithersburg shop and we will diagnose it at the counter.
Frequently Asked Questions
What does Dolly Kit actually mean?
It is the kit numbering used for rebuild parts fitting the AR, CAT, and General Pump heads common on cart and dolly style pressure washers. Each kit bundles the valves, packings, or plungers for a specific pump series.
Do I need a valve kit or a packing kit?
Surging and pressure that swings up and down point to valves. A slow fade in pressure over weeks, or water dripping from the weep holes, points to packings. If the head is already open, do both and skip the second teardown.
How do I find which kit fits my pump?
Read the model number off the pump data plate, not the machine frame. The engine brand tells you nothing about the pump. With the pump model and plunger size, the kit number is a one minute lookup. Send us a photo of the plate if the sticker is half gone.
Why does my CAT pump need two valve kits?
CAT packages some valve kits to cover half the valves in a 3CP or 310 series head. Servicing the whole pump takes two kits. It surprises people mid-rebuild, so order both up front.
I replaced the packings and it still leaks. Now what?
Check the plungers. Scored or cracked ceramic cuts new seals fast. Run a fingernail across each plunger, and if you feel a ridge or see a crack, install a plunger set with your next round of packings.
Is rebuilding worth it compared to a new pump?
Usually. Most kits here run $17 to $102, and a full valve plus packing rebuild lands near $100 on common AR models. A comparable replacement pump starts around $500. Unless the crankcase is damaged, rebuild it.