DZ21 ... deck raising so ... pump?

xtal_01

New member
May 20, 2022
6
0
1
Jericho, Vermont
Hey!

Looking at an old DZ21.

They guy says the deck raises very slow.

When I pressed him, he said it was the pump (not sure how he would know but he did just have it serviced ...maybe that is what he was told by the dealer).

So two questions:

First ... I am looking at a parts diagram for the unit. Is the lift pump the pump that is right where the driveshaft goes into the transmission?

Are there more than 1 pump ...maybe 1 lift pump and a pump for the drives?

Second ... is the pump the most likely issue or could it be the valve or cylinder or ???

Thanks!

Mike
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,207
1,893
113
Mid, South, USA
there is one pump. It supplies the HST's also, called "charge pump". If the charge pump is "bad", I can almost guarantee you that the HST's are also going to go south-if they haven't already. Done a bunch of them. All expensive.

Could be the valve, or could be the cylinder. Only way to diagnose properly is with a pressure gauge.

If it's cheap enough to gamble, might pick it up and hope it's just a relief valve sticking. But assume that the pump is bad and assume the hst's aren't far behind. I'm thinking about $3000 for the hst's and the charge pump is not out of line. So use it to bargain, deduct that from whatever he's asking for it.
 

xtal_01

New member
May 20, 2022
6
0
1
Jericho, Vermont
there is one pump. It supplies the HST's also, called "charge pump". If the charge pump is "bad", I can almost guarantee you that the HST's are also going to go south-if they haven't already. Done a bunch of them. All expensive.

Could be the valve, or could be the cylinder. Only way to diagnose properly is with a pressure gauge.

If it's cheap enough to gamble, might pick it up and hope it's just a relief valve sticking. But assume that the pump is bad and assume the hst's aren't far behind. I'm thinking about $3000 for the hst's and the charge pump is not out of line. So use it to bargain, deduct that from whatever he's asking for it.
I am sooooo glad you chimed in!

I really need a mower ... mine died.

I have never had a zero turn ... just a 16 year old cub cadet.

I have about 2 1/2 - 3 acres to mow

It took me 5 hours on my mower.

I borrowed a DZ21 from the neighbor twice ... 2 - 2 1/2 hours to mow.

I found this one ... it is two hours away from me ... ad says:

"Zd21 1673 hours just serviced still using it to mow only issue is deck picks up slow msg for more info 3 cylinder diesel"

I asked him since he had it serviced, what was wrong with the deck (valve, pump or ???) ... he came back "it is the lift pump"

OK, so you are saying there is no lift pump, just the pump I am looking at called the "charge pump"

He is asking $3500

If the HST's are on the way out then I would have $$6500 in a 20 year old mower ... probably not a wise move.

He says it only has 1673 hours on it .... would the pump and motors be gone with so little hours (if you believe the meter)?

The hone I borrowed has over 5000 hours on the original pump and motors.

Is the only way to check using a pressure gauge?

If it drives correctly but does not lift then can I "assume" (hate that word) that it is the valve and not the pump?

Valve is not cheap ... Merricks $657 plus shipping

I appreciate the advice.

Mike