ARYEIELLSOW 1 PACK 630-7755 Wall Hydrant Service Repair Kit Compatible With Mansfield Prier Faucet 300, 400 and 500 Series Wall Hydrant

Why I reached for this kit

A slow drip at the spout and a faint weep from the handle on a frost‑free wall hydrant is the kind of nuisance that can waste water all season. Rather than replace the entire faucet, I tried the 630‑7755 repair kit to see if I could rebuild the valve in place. I was after a kit that covered the common Mansfield styles (300/400/500) and Prier equivalents without sending me on a hunt for one obscure washer. This one promised broad compatibility and an install with basic hand tools. That’s exactly the experience I had—mostly.

What you actually get

The 630‑7755 kit is a full assortment of seals, packings, washers, and small hardware meant to refresh the stem and packing assembly on freeze‑resistant wall hydrants. It includes:

• Multiple stem/end washers for different series
• Graphite packing for the handle/packing nut
• O‑rings and bonnet/packing seals
• A mix of screws and small hardware
• Left‑hand and right‑hand options to suit the various model orientations

It’s more parts than you’ll use on a single hydrant, and that’s the point: the kit aims to cover the popular Mansfield 300/400/500 series and compatible Prier models (including certain 300/400/408 variants). I appreciated having options on the bench so I could match old to new without guessing.

Build quality is generally good for a universal kit. The graphite packing is a standout—it’s the right choice for stopping a handle seep without overtightening. Some of the softer packing rings are on the delicate side; if you’re heavy‑handed with the packing nut, you can deform or nick them. Take your time, lube threads lightly, and snug rather than crank.

Compatibility and fit

I rebuilt a Mansfield‑style 400 with this kit and had everything I needed to stop both the spout drip (stem washer) and the handle weep (graphite packing). I also refreshed an older Mansfield 300 where the stem washer swap and packing did the trick, but I had to pay closer attention to left‑hand vs right‑hand parts during reassembly.

On a late‑1990s Prier 400‑series hydrant, I ran into a minor hiccup: the specific flat end washer required by that stem variant wasn’t an exact match from the assortment. The fix was simple—I grabbed a common flat washer locally to complete the job and used the rest of the 630‑7755 parts without issue. Chalk that up to the reality that Prier has produced a lot of small variations over the years; most are covered, a few might need a single commodity washer.

Bottom line: if you correctly identify your series and match old parts to new, you’ll likely find what you need in this kit. It’s an excellent fit for Mansfield 300/400/500 and many Prier 300/400/408 hydrants. If your hydrant has a very specific end‑washer dimension, be prepared to source that one piece.

Installation: straightforward if you prep

The install itself is well within DIY range. Here’s what worked for me:

• Tools: screwdriver, adjustable wrench, pliers, a small pick, and gloves. A dab of silicone grease helps.
• Shut off the water, open the hydrant to relieve pressure, and let it drain.
• Back up the hydrant body with a wrench inside if accessible so you’re not twisting supply piping while you loosen the stem/bonnet assembly.
• Remove the handle and packing nut, then withdraw the stem.
• Lay the parts out in order and photograph the assembly as you go—this helps with left‑hand vs right‑hand orientation.
• Replace the stem/end washer and screw, the packing/packing nut seal, and any O‑rings that match your originals.
• Reassemble, snug the packing nut, turn on water, and fine‑tune the packing nut until the handle turns smoothly without seepage.

Start to finish—including clean‑up and a quick flush of debris from the line—the first job took me about 40 minutes. The second was closer to 25. The biggest time saver was keeping the old parts on the bench so I could visually match them to the kit.

Performance and durability after the rebuild

Functionally, the improvement is immediate. The spout drip stopped as soon as the new stem washer made contact, and the graphite packing sealed the handle without the gritty feel you get when you overtighten old packing. The hydrant opened and closed smoothly, and freeze‑resistant functionality was unchanged (as it should be—the kit doesn’t alter the body or seat).

Weeks later, both hydrants were still dry at the handle and tight at the spout. I did go back once to give the packing nut a light nudge; new packing can settle slightly. No signs of premature wear so far.

Documentation and ease of use

The included instruction sheet covers multiple series and has helpful diagrams, but the type is small and the illustrations are cramped. If your eyesight or workspace lighting isn’t great, plan to supplement with a quick schematic from the manufacturer’s website or a brief video for your exact series. The kit assumes you’ll identify and match your parts rather than follow a single, model‑specific flow.

A practical tip: mark the stem orientation before removal and keep parts in order on a cloth. It’s easy to mix up a left‑handed component and spend time retracing your steps.

What this kit will—and won’t—fix

• Will fix: drips from the spout caused by a worn end washer; weeping from the handle/packing nut; minor weeps at bonnet seals; general stem/packing refresh on Mansfield 300/400/500 and many Prier 300/400/408 styles.
• Won’t fix: a damaged or pitted valve seat inside the hydrant body. If the seat is nicked or corroded, a new washer won’t seal perfectly. You’ll need to reface the seat (if the design allows) or replace the hydrant. Likewise, cracked castings or severely corroded stems are outside the scope of any seal kit.

Value and alternatives

Compared to OEM kits, this universal set is cost‑effective and broadly applicable. You’ll typically use 10–30% of what’s in the bag for a given repair, but that flexibility is the value proposition. The leftover parts are useful spares if you maintain multiple hydrants or have both Mansfield and Prier styles on the property.

If you know your exact model and prefer a one‑to‑one match with fewer variables, a model‑specific OEM kit remains the easiest route. For mixed inventories or uncertain series numbers, the 630‑7755 kit strikes the right balance of coverage and price.

Tips to get it right the first time

• Confirm your series (300/400/500) and brand before you start; measure the existing end washer.
• Photograph each stage of disassembly.
• Don’t overtighten the packing nut; use graphite packing and sneak up on the seal.
• If the spout still drips after a new washer and screw, inspect the valve seat with a flashlight before you blame the parts.
• Consider keeping a small assortment of common flat washers on hand; it can save a trip if your stem needs a specific size the kit doesn’t include.
• Back up the supply line with a second wrench to avoid stressing interior plumbing.

Pros and cons

Pros:
- Broad compatibility with Mansfield and Prier series
- Includes left‑ and right‑hand components and graphite packing
- Installs with basic tools in under an hour
- Cost‑effective versus replacing the hydrant

Cons:
- Instructions are small and generic; online diagrams help
- Some packing components are easy to damage if overtightened
- A few Prier variants may need a specific end washer not exactly matched in the kit
- Not a solution for damaged valve seats

Recommendation

I recommend the 630‑7755 repair kit for homeowners and maintenance pros looking to refresh Mansfield 300/400/500 and many Prier 300/400/408 wall hydrants without replacing the entire unit. It’s a practical, budget‑friendly assortment that covers the most likely failure points—spout drips and handle weeps—and installs with common tools. Be realistic about what a seal kit can do: it won’t fix a bad seat, and a small subset of Prier stems may need a specific flat washer sourced separately. If you’re comfortable matching old parts to new and taking a measured approach to packing adjustment, this kit is an easy win that restores function and stops the drip.