Glow Plugs...

[moship]

Recording this info in the event it helps anyone down the line.

Summary:

Glow Plugs: 19077-65512, 19077-65511, 19077-65510, 1J860-65510, 1J860-65510, 1J860-65511, 1J860-65512 are all linked as similar using Kubota's Illustrated Parts and Messick's.

GP price is different depending on PN. Surprising given they are functionally the same.

Kubota 19077-65512 is actually a NGK Glow Plug Part number: Y-716RS, stock number: 4693 (Rockauto has them for <$15)

GP Nut size: 7mm

GP itself: 12mm (deep socket)

NGK Data: https://www.ngkpartfinder.co.uk/files/NGK_Glow-Spec.pdf



The long story:

My tractor seemed to take a bit longer to start when cold (30F and below) than I thought it should. My expectation is it starts within 2-3 seconds of crank time. Anything longer seems unacceptable. It has always started, but I always questioned if the glow plug (GP) circuit was operating as designed and I questioned the short on time the dash calls for the GP to be energized. So it was time to investigate if all is functioning as it should with respect to the GP circuit.

Started by ensuring the battery is fully charged. Battery terminals and connections cleaned using a wire brush or sandpaper to ensure good metal to metal contact. Fuel is recently purchased and Power Service (white) and biocide added every time.

To measure supply voltage to the GP buss bar the GPs must be removed from the circuit. Otherwise you will not see battery voltage on the meter. On cab tractors there is a wire connector that can be disconnected and voltage measured at that point. (See photo) Great battery voltage is confirmed to the GPs.

Accessing GPs:

The nuts used to hold the buss bar to the GP are 7mm. They can all be accessed and removed using 1/4 ratchet with short and longer extensions. To keep from losing the nuts, a rare earth magnet was placed on the socket. Nuts are the flange type with knurling on the buss bar side, so no lockwashers are used. In some instances it was easier to access the GP's from the muffler side (left side).

With the buss bar removed from the GP the resistance can be checked against spec. Great all four are similar each other measuring approximately 0.9 ohms (within spec according to WSM).

To visually inspect one GP was removed using 12mm deep socket. The GP looks to be in great shape. Sheath is clean, no blister or other overheat indications, terminals free of corrosion. Feel good about the appearance. Confirmed resistance again while it was removed. (Reference photo)

Decided to hook up the GP to fully charged battery to see how long it takes for them to glow. Wow! It takes approximately 4 seconds (at most) to see a very nice glow at the tip. Now I feel a lot more confident the short GP dash indication is justified.

Put everything back together and it starts as it should... Maybe a bit quicker - possibly due to the clean electrical connections or just a placebo effect.

I really didn't find anything, but there was some evidence of slight corrosion at the GP buss bar white connector (maybe on cab models only), and it never hurts to clean the battery terminals including the chassis side of the battery ground. It does give me more confidence knowing the GP circuit is working as it should.

Tractor Model: L4740-3 HSTC

The stock Kubota glow plug (19077-65512) is actually a NGK part number: Y-716RS, stock number: 4693 (see photo). For reference: Kubota $31.71 Rock Auto $ 15.54

NGK can also be found at Napa or others. If you can't find it using the NGK part number, use the stock number.

In researching the current glow plug part number, I found a number of Kubota GP's are interlinked.

19077-65512 replaces 19077-65511 (Messick's) & 19077-65510 (Kubota's illustrated parts show 66512 = 66510)

Using 19077-65510 was replaced by 1J860-65510 which was replaced by 1J860-65510 $21.79 (Used Messicsk's to research 19077-66510)

1J860-655110 was replace by 1J860-65511 replaced by 1J860-65512 (Messick's)

The Kubota P/N (19077-65512) is used on the following models (according to Messick's great website).

The part fits the 90 models listed below:

KJ-S130D-USA, KJ-S150V-USA, KJ-S150VX-USA - 120601 NOZZLE HOLDER AND GLOW PLUG, KJ-S150VX-USA - 120602 NOZZLE HOLDER AND GLOW PLUG, KJ-T210V-USA, KJ-T210VX-USA - 120601 NOZZLE HOLDER AND GLOW PLUG, KJ-T210VX-USA - 120602 NOZZLE HOLDER AND GLOW PLUG, KJ-T270F-SW-USA, KJ-T270FX-SW-USA - 220601 NOZZLE HOLDER AND GLOW PLUG, KJ-T270FX-SW-USA - 220602 NOZZLE HOLDER AND GLOW PLUG, KX121-3ST (SN : 70000- / Super Series / Tier 4), KX161-3ST (SN : 70000- / Super Series / Tier 4), KX91-3S2 (SN : 40000- / Super Series / Tier 3)

L2800DT / HST (Dual Traction 4wd / Hydrostatic Transmission), L2800F (2wd),

L3200DT (Dual Traction 4wd), L3200F (2wd), L3200H (Hydrostatic Transmission),

L3240DT / GST (Dual Traction, 4wd / Glide Shift Transmission / Rops / 2007 - 2009), L3240DT-3 (Dual Traction 4wd / Rops / 2010), L3240F (2wd / Rops / 2007 - 2009), L3240F-3 (2wd / Rops / 2010), L3240GST-3 (Glide Shift Transmission / Rops / 2010), L3240HST (Hydrostatic Transmission / Rops / 2007 - 2009), L3240HST-3 (Hydrostatic Transmission / Rops / 2010), L3240HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L3240HSTC-3 (Hydrostatic Transmission / Cabin / 2010),

L3400DT / HST (Dual Traction 4wd / Hydrostatic Transmission), L3400F (2wd)

L3540GST (Glide Shift Transmission / Rops / 2007 - 2009), L3540GST-3 (Glide Shift Transmission / Rops / 2010), L3540HST (Hydrostatic Transmission / Rops / 2007 - 2009), L3540HST-3 (Hydrostatic Transmission / Rops / 2010), L3540HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L3540HSTC-3 (Hydrostatic Transmission / Cabin / 2010),

L3700SU (Hydrostatic Transmission, 4wd / Special utility), L3800DT (Dual Traction 4wd), L3800F (2wd)

L3800H (Hydrostatic Transmission),

L3940DT / GST / HST (Dual Traction, 4wd / Glide Shift Transmission / Hydrostatic Transmission / Rops / 2007 - 2009), L3940DT-3 (Dual Traction 4wd / Rops / 2010), L3940GST-3 (Glide Shift Transmission / Rops / 2010), L3940HST-3 (Hydrostatic Transmission / Rops / 2010), L3940HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L3940HSTC-3 (Hydrostatic Transmission / Cabin / 2010)

L4240DT / GST / HST (Dual Traction, 4wd / Glide Shift Transmission / Hydrostatic Transmission / Rops / 2007 - 2009), L4240DT-3 (Dual Traction 4wd / Rops / 2010), L4240GST-3 (Glide Shift Transmission / Rops / 2010), L4240HST-3 (Hydrostatic Transmission / Rops / 2010), L4240HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L4240HSTC-3 (Hydrostatic Transmission / Cabin / 2010)

L4400DT (Dual Traction 4wd), L4400F (2wd), L4400H (Hydrostatic Transmission)

L45

L4740GST / HST (Glide Shift Transmission / Hydrostatic Transmission / Rops / 2007 - 2009), L4740GST-3 (Glide Shift Transmission / Rops / 2010), L4740HST-3 (Hydrostatic Transmission / Rops / 2010), L4740HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L4740HSTC-3 (Hydrostatic Transmission / Cabin / 2010)
L48

L5040GST (Glide Shift Transmission / Rops / 2007 - 2009), L5040GST-3 (Glide Shift Transmission / Rops / 2010),

L5240HST (Hydrostatic Transmission / Rops / 2007 - 2009), L5240HST-3 (Hydrostatic Transmission / Rops / 2010), L5240HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L5240HSTC-3 (Hydrostatic Transmission / Cabin / 2010)

L5740HST (Hydrostatic Transmission / Rops / 2007 - 2009), L5740HST-3 (Hydrostatic Transmission / Rops / 2010), L5740HSTC (Hydrostatic Transmission / Cabin / 2007 - 2009), L5740HSTC-3 (Hydrostatic Transmission / Cabin / 2010)

M5140DT (Dual Traction 4wd / Rops), M5140DTC (Dual Traction 4wd / Cabin), M5140F (2wd / Rops), M5140FC (2wd / Cabin), M5140HD, M5140HD (Hydraulic Shuttle, 4wd / Rops), M5140HDC, M5140HDC (Hydraulic Shuttle, 4wd / Cabin)

M5640SU (Special utility 2wd), M5640SUD (Special utility 4wd), M5640SUD / SUD-1 (Special utility 4wd)

M59

MX4700DT (Dual Traction 4wd), MX4700F (2wd), MX4700H (Hydrostatic Transmission),

MX5100DT (Dual Traction 4wd), MX5100F (2wd), MX5100H (Hydrostatic Transmission)

R420S

R520S - 020602 NOZZLE HOLDER AND GLOW PLUG, R520S - 020603 NOZZLE HOLDER AND GLOW PLUG

U35-S2 (SN : 40000- / Super Series / Tier 3), U45ST (SN : 70000- / Super Series / Tier 4)

 

[JWR]

Whatever it is , you must have it covered.

My only comment is that 2-3 seconds is an unreasonable expectation for glow plug time in colder weather. At least with smaller Kubotas the glow plug time "on" needs to be 5 or 6 seconds at 30 degrees OAT in order for a responsive start. Maybe even a little longer on the plugs. Now granted, you can run the plugs less time and crank the engine more and, yes, it will start grudgingly and slowly. I see the smoother approach is to run the glow plugs long enough such that the engine starts quickly and effortlessly when it does crank.

 

[moship]

My only comment is that 2-3 seconds is an unreasonable expectation for glow plug time in colder weather.

Thanks for the feedback...

The 2-3 seconds is with respect to the starter/crank time and not the GP on time.

The GP on time is not operator controlled. The computer dictates how long the GP is energized and dependent on coolant temperature. The starting sequence is to put the key in run, wait for the GP dash light to go off and then start.

In colder weather the GP's are activated much longer than the 4 seconds it takes for the GP to turn red hot.

I thought the NGK # might help others with alternatives to purchasing directly from dealer whether it be based on cost, convenience or availability.

 

[newbury]

Good detailed write up. Thanks.

 

[JWR]

Thanks for the feedback...

The 2-3 seconds is with respect to the starter/crank time and not the GP on time.

The GP on time is not operator controlled. The computer dictates how long the GP is energized and dependent on coolant temperature. The starting sequence is to put the key in run, wait for the GP dash light to go off and then start.

In colder weather the GP's are activated much longer than the 4 seconds it takes for the GP to turn red hot.

I thought the NGK # might help others with alternatives to purchasing directly from dealer whether it be based on cost, convenience or availability.

OK, I misunderstood. The smaller Kubota's are a manual selected period of time for the GPs to glow. Yes, once the GPs have warmed things up in there, my BX2200 starts immediately, I would say only 2 or 3 revolutions of the crank if that. Same thing with my larger MF2660 using a Perkins 81 horse diesel. Maybe there is a setting in your system for increasing the GP "on" time before cranking ?

 

[FatTire]

Did you have remove anything (like the fuel tank) in order to pull the GP's?

 

[moship]

Did you have remove anything (like the fuel tank) in order to pull the GP's?

I only removed one glow plug. The easiest to access. (It was a bit too cold and a storm was pending to risk running into difficulties removing the end ones.)

All four GP's were tested after the buss bar was removed. This could be done without removing anything.

The GP located closest to operator looks questionable if it can be removed due to the fuel tank. The one closest to the radiator also looks questionable due to the AC compressor and supporting bracket for windshield washer fluid.

In other words the middle ones are easy to remove and the ends questionable. I think it's possible for the end ones to be removed and might give it another go when I find time.

The other day it was approximately 15F and it took several GP cycles and a long crank time to start. I'm a bit surprised that after the 10-13 seconds of GP activation there isn't enough to GP heat to start withing 4 seconds of crank time. (Battery is fully charged and I verified state of charge based on specific gravity and ambient temperature. Crank speed seems fast). These glow plugs look white hot in 4-5 seconds.

 

[FatTire]

Thanks Moship, appreciate all the part no. info. On a 5cyl Mercedes engine I had one dead GP and replacing it made a surprisingly big difference starting at 15 to 25F.

 

[bunyip]

I had a glowplug problem on a Diesel Toyota, the pre heat timer was not turning off, I disconnected it and used a jumper to the GP's and blew all of them.
Discovered afterwards that they were 6volt despite being a 12v vehicle and the dropping circuit was via two big GP's in the manifold.
I am now aware of what little surprises GP's can have in store for the unwary.

 

[The Fred]

Thanks for the nice write up. I check amperage rather that voltage, since each glow plug draws about 20 amps cold then a 3 cylinder will draw 60 amps and as the plugs warm they draw less. It's an easy check around that wire you showed with a cheap amp clamp.

The other thing you can check for slow starting is the starter revolutions while cranking, faster is better. My 3940 doesn't seem to have much cranking speed but always starts. Mine cranks around 225 RPM (checked with a labscope on the crank sensor by the fuel pump) and that's not very fast.

Regards, Fred