Do HST filters have Bypasses?

[racerboy832]

I'm trying to match up filters for my Deutz Allis 5220 HST. Dealer wants $100 each for HST and Hydro filters. The HST filter from the dealer shows it as an element but it is a spin on. Wix # 51736 is a dead on copy of the filter I have from a measurement point. Only one I can find on the net with the nut on the back too. I looked inside the filter and don't see a bypass Valve but that doesn't mean there wasn't suppose to be one. Generally speaking do HST filters have a bypass or maybe there is one made into the mount. The 8" long Hydrofilter (Wix 57300) looks like there is one in the bottom of the one on the machine. The only thing i'm not sure about is what the Min Micron size I need and the bypass valve.

 

[zman007007]

Since you have numbers and name brand , call someone else like Napa and see if they can cross them over for you. It will be a lot cheaper. zman:thumbsup:

 

[sandman2234]

Before I spent $100 on a filter, that would need changing often, I would investigate plumbing in an aftermarker filter base and use a different filter, but a GOOD one. Maybe even add a pair inline of each other to protect the system even more, or at least plumb in an extra prior to the original, to extend the life and usefulness of the original. All of this will be conditional of available room, however.
David from jax

 

[J_J]

The bypass, is located in the filter housing. Some even have a gage, or other indicator to remind you to change. If you don't have the gage or other indicator, you may be bypassing and not know it.

http://www.tpub.com/content/engine/14105/css/14105_147.htm

 

[racerboy832]

The thing that kinda throw me off is all the bypasses I have seen pop off at 11-20 PSI. If the HST Charge is suppose to run at 60-90 PSI to the Transmission pump wouldn't it always blow open the valve? I can see the Hydraulic Suction filter having a bypass like the one that came off it but it's this HST filter that i'm concerned about. I'm not trying to be cheap cause I want my tractor to last but $100 a filter just doesn't seem correct if they can even still get me the ones I need.

 

[RickB]

The bypass, is located in the filter housing. Some even have a gage, or other indicator to remind you to change. If you don't have the gage or other indicator, you may be bypassing and not know it.

Figure 9-11.—Full-flow bypass-type hydraulic filter (with contamination indicator).

Many spin on filters have a bypass valve within.

 

[J_J]

I have a hydrostatic transmission on my Power-Trac, and the suction filter is before the charge pump, and the bypass is in the housing.

 

[racerboy832]

JJ, I think I misread your post. The Bypass is in the filter Base not in the filter on the HST side. That makes more sense. When I took both filters off ,the HST Filter is about 6" long with a Nut on the back and is yellow. The Suction Filter is about 8" Long and is just plain white. If I look in the filter opening at the bottom there is a metal piece sticking straight up and it wiggles. I assume this a bypass for the big filter.

The HST Filter says 2c10 on it. But that's all.

 

[RickB]

I have a hydrostatic transmission on my Power-Trac, and the suction filter is before the charge pump, and the bypass is in the housing.

I don't doubt that. But there are plenty of spin on filters in this world with bypass valves. Statements such as "The bypass, is located in the filter housing" need to be directed towards a particular application where it is valid, not spread like a blanket.

 

[J_J]

Maybe so, but are you saying that filters assembly's that have bypass valves inside the filter , have no bypass valves in the filter housing?

 

[RickB]

Maybe so, but are you saying that filters assembly's that have bypass valves inside the filter , have no bypass valves in the filter housing?

I posted nothing either way regarding bypass valves in filter housings beyond calling you out for suggesting that the filter bypass is located in the filter housing, which I took to mean the filter head. Your post allowed for no exceptions and therefore is false and does no service to the poor guy trying to match filters. Neither you nor I have a clue as to whether a Deutz-Allis 5220 has hydraulic and/or hydrostatic filter bypass mechanisms or where they may be located. A proper filter cross-reference will include an element with the proper bypass valve if one is required. That's all the OP is looking for.

Wix lists a hydraulic cartridge filter #51257 and #15250 housing o-ring for a 5220 HST. They have no listing for the hydrostatic filter. This means that probably NAPA and CarQuest can get that filter, as Wix supplies both retailers. Baldwin lists no hydraulic system filters for a 5220. Fleetguard only lists an outer air filter. The OP is probably going to have to pony up for OEM filters.

 

[J_J]

Correction to my last.

Q: Do hydraulic filters have bypass valves?
A: Hydraulic filter bypass valves if present are typically located in the filter head assembly or a separate component to the hydraulic system.

 

[racerboy832]

Oh boy, I hope I didn't start a fight over a simple ?. My Question was, Do HST Filters (Not regular Hydraulic filters) have a bypass in them. I've looked up everysize 1-1/8 X 16 filter I can find. The one that is made by Wix that is a dead ringer physically to what is on my machine does not have a bypass setting. The one I took off my Machine Does not appear to have a bypass. If the HST filter mount has some sort of bypass in it then this filter I looked up in theory should be fine. If you told me that HST filters have bypass in them 99% of the time they i'd say, oh shoot I guess I better keep looking for other filters. I'm just playing process of elimination before I try the Wix filters. If the OEM Filters weren't $100 each I would just buy them. The dealer doesn't even know if he can find them both since it shows one as a cartridge and mine both are spin ons.

 

[Chilly807]

The actual system oil pressure has little effect on the bypass mechanism, it could be 200 psi and still not open a 15 psi bypass. The bypass is designed to work on differential oil pressure, i.e. if the pressures before and after the filter differ by more than a set value (15 psi for example), the bypass will open and allow at least some flow past the valve.

The thinking is that if the filter is starting to restrict oil flow enough to reduce the pressure by an appreciable amount, it is dirty. A lot of heavy diesels have two oil pressure gauges, one before the filter and one after. The operator can see easily how much restriction is in the oil filter. Some have idiot lights based on oil pressure differential values.

Sean