Pictorial DIY for repairing Wilkins Zurn 975XL Backflow Preventer

[Danny D.]

So that others can find it more easily, here is a step-by-step pictorial DIY showing each step in my repair today of my

1" ID Wilkins Zurn 975XL Backflow Preventer, thanks to your help at alt.home.repair.

STEP 0: Shut inlet & outlet valves & open #2,#3 & #4 test ports STEP 1: Repair & clean the #1 check valve on top inlet STEP 2: Repair & clean the #2 check valve on bottom outlet STEP 3:Repair & clean the relief valve on the side inlet

IN SUMMARY: I found all the parts inside the three valves in excellent condition as you had suggested it would be - but I replaced them all anyway.

The key problem I saw was the #2 check valve was stuck in place due to light-green corrosion inside the brass cap cavity.

Also there was light-green corrosion in all cavities, which I painstakingly wire brushed out - as that was the key issue.

On a scale of 1 to 10, this is an easy 1. No surprises. No special tools. It took me about three hours - one hour for the #1 check valve on the top inlet, another hour for the #2 check valve on the bottom outlet, and another hour for the relief valve on the inlet.

It should take you about a half hour in total - maybe 45 minutes, depending on how well you wish to clean out the green corrosion. I took my sweet time.

Below is a quick DIY with photographs for the $755 1-inch ID Zurn Wilkins 975XL Reduced Pressure Principle Backflow Preventer

after detailing the 11-piece Wilkins Water Works RK34-975XL $43.20 repair kit (855-663-9876) and assembly instructions.

HERE ARE THE KEY REFERENCES: Wilkins Zurn 975XL Specification Sheet

Wilkins Zurn 975XL Maintenance Sheet

[Danny D.]

Thanks Oren.

Coming from you, that's a big compliment. I didn't write all the steps because they're in the PDF that I referenced in the end. But the PDF suffers in that it doesn't show the pictures of the steps.

So, with the PDF & pictures combined, anyone can perform this repair easily. I realize Smitty Two doesn't like my OCD style - but I start knowing nothing and, with your help plus my research, I end up knowing 'enough' to try to teach the next guy. That's what I live for. To learn & to teach.

Some day, I'd like to write a HOWTO DIY book that is written how I would want it (with no step left to the imagination). I realize 99% of the people out there are just fine with the missing steps or with figuring out things as they go along; but, for me, I like to see everything before I do it.

One day I'd like to buy a house and just take everything apart and make a book out of it. Maybe I should start simple, as with just a car huh!

I wonder if it would sell enough to make that DIY hobby of mine worth it?

BTW, 'm shocked at the $755 (list) price of my $755 backflow preventer. I just don't get why it's $600 more expensive than similar three-valve systems at Sears.

Any idea why 'this' particular backflow preventer is 7 times more expensive (list) than similar ones?

[Robert Green]

Remarkably complete and concise and what Usenet *should* be about. Even more refreshing to stumble across after 50 messages from Sad Sacks with nothing better to do than use Usenet like their own personal playpen.

Thanks for reminding me there are still some responsible adults left willing to put in the effort it takes to share their knowledge and experience with others. It's inspiring.

-- Bobby G.

[Danny D.]

Thanks for recognizing that effort.

I have been on USENET since the days of tin & rn and well before Google or Netscape ever existed so I've seen the good and bad (although my nym changes frequently for privacy reasons).

I, for one, will always be responsive to each sincere post; I will always provide a followup update when complete; and I'll try to stay on topic (at least per post); and, most importantly, I'll try to provide enough detail, as I learn the answer to the question at hand, so that the next person who follows in our footsteps has the benefit of standing on our shoulders.

Thanks for recognizing that effort. Kudos to all for this wonderful alt.home.repair NNTP newsgroup - which - we might agree - is one of the best of the net due to the people who post on it.

[oktallfamily]

Danny - your post is exceptional. This is exactly the way I approach repai rs. My relief valve is spewing like crazy and (after shutting off the ball valve) while I was waiting for a call-back from some sprinkler guy I walke d through your instructions. I opened mine up and found that the head of t he diaphragm stem (flange that holds the o-ring that seals it at the relief port) was quite bent. As soon as I get a replacement, we'll see if that f ixes it. Anyway, thanks for taking the time to post this info. Tom

[donrmabry]

Danny, Struggling with same - trying to DIY repair of my 975XL. Much thanks for your efforts.

Sincerely, Don Mabry Nashville, TN

[clark]

I have a Wilkins Zurn 975XL, but I can't tell from looking at it whether it's a model RK34 or RK114. Any ideas how to know definitively? Thanks!

[Walter Heger]

The model number is on the top cap. see

If they look alike, they probably are. I think the 975XL is made with lead, and the 975XL2 is lead-free. The other major difference is the diameter of the pipes. 3/4 1, 1.5, 2 inches. Looking at youtube, the other Wilkins-Zurn seem to have common gasket sizes at least on the plungers.

[Walter Heger]

RK34_has_springs

[Walter Heger]

there are 2 repair_kits. RK34 has springs.the_other_one_does_not