D9H 90V4688 foot brakes seem to have lost hydraulic pressure. The right side pedal pressure has been non existent since I’ve owned the machine, but the left had worked good, stopped the dozer even on an incline up until a few days ago. The dash steering levers work great. To narrow the problem down will it take pressure testing or does something seem stand out? Linkage is adjusted properly and fluids are good. Thx
-
Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
D9H foot brakes
- Thread starter Bjt
- Start date
Take the two covers off on the rear of machine that are circled in the picture. There’s a 3 bolt cover on the top of each side of the housing. Take it off and put a socket on the drive inside the hole. Tighten until it makes contact and then back off 9 clicks. Repeat for the other side.
After adjusting both sides and backing off 9 clicks the left brake pedal works great but the right pedal doesn’t brake as good. Would it cause problems to back the adjuster off only
7-8 clicks as long as the brake is not dragging, instead of 9?
7-8 clicks as long as the brake is not dragging, instead of 9?
Check Break
Senior Member
Pull your transmission filters and look for brake material. Sounds like your right brake has reached the end of its service life. If it has and starts coming apart in chunks, it will take out your transmission filters and you'll be dealing with a much more expensive problem.
Got around to changing and cleaning the transmission filters. There was fine metallic particles on the magnets and some small rust like flakes. This dozer had set for 21 years until I bought it. Since then there’s been around 500hrs worth of run time on 2 tranny oil changes. Could this be an indicator of a brake coming apart?
Shimmy1
Senior Member
This is the actually the third filter change and magnetic screen cleaning along with the oil during the time I have owned the machine. First change and cleaning was as soon as I got it home with only a few minutes run time, just long enough to load and unload. The previous owner had installed a new torque converter because of overheating issues also. Could this be material left over from the previous TQ and the years of sitting maybe?
.RC.
Senior Member
Sounds to me like the problem may be in the brake actuator itself. It the design is similar to the smaller tractors of that era. The brake pedals go into the brake actuator housing on either side and there is a spool valve in there the foot brakes press on to give you power brakes using the foot pedal. They are also directly connected to the brake band so you still have brakes of sorts when the engine is stopped and there is no oil pressure. This is totally independent from the hand levers.
I imagine to get access to the actuators, you will have to tip the cab and remove the fuel tank.
I imagine to get access to the actuators, you will have to tip the cab and remove the fuel tank.
Check Break
Senior Member
The short answer is no. I doubt the fuzz in your screen is related to the converter or brake band. Might be brake drum material. Might be the aftermath of a catastrophic failure that wasn't cleaned out properly. I don't know my way around a 9H but they're similar to an 8K and there should be more screens. Do they look the same. Did this screen look the same when you brought it home. Is the amount of material on the screens decreasing or increasing. Realistically, you have 500 hours and two filter changes since you've owned it. That's a lot of material for 250 hours of operation. I used to know a mechanic who left a lot of material in the bevel gear compartment. He used to say, "that's what filters are for." Hopefully he worked on your 9H and that's all that's going on.
The first time cleaning the suction screen there was a
lot of rust flakes, not so much the second cleaning. The third time hardly any flakes but a bit more fuzzy metallic particles. The torque converter screen was clean the first time so I didn’t bother with it the last cleaning. Unaware of any other screens. I readjusted the brake that doesn’t seem to have good hydraulic power tighter by 2 clicks and ran it for 15-20 hrs but it didn’t help. I’ll look into the brake actuator and readjust the brake band back to spec. There’s a good chance the same mechanic repaired this dozer too, because it does have a cat reman sticker on the tranny.
lot of rust flakes, not so much the second cleaning. The third time hardly any flakes but a bit more fuzzy metallic particles. The torque converter screen was clean the first time so I didn’t bother with it the last cleaning. Unaware of any other screens. I readjusted the brake that doesn’t seem to have good hydraulic power tighter by 2 clicks and ran it for 15-20 hrs but it didn’t help. I’ll look into the brake actuator and readjust the brake band back to spec. There’s a good chance the same mechanic repaired this dozer too, because it does have a cat reman sticker on the tranny.
pittsburgh cat man
Senior Member
90vs have a habit of cracking the top cover around the piston bore
Check Break
Senior Member
Sounds like she's making metal. Do you know when the reman transmission was installed. If it wasn't the original transmission and no concern was given to the cross shaft, the pinion may be tight. You're probably going to have to pull the brake covers to fix your brake problem so you can get a good look at everything when you're in there.
No idea when the transmission was installed but was able get in touch with the last two of the previous owners mechanics. The owners have passed. According to both no transmission work was done during their ownership. A new torque converter, reman heads and brake bands is all the repairs they could remember between the both. When I get to the brake covers to inspect for cracks I’ll check the cross shaft too.
.RC.
Senior Member
I can see what chidog is doing.
He is running down all these older machines to tank their prices. Then he will step in and buy all these cheap machines. Then as demand picks up, he will sell them off for a big profit.
He is running down all these older machines to tank their prices. Then he will step in and buy all these cheap machines. Then as demand picks up, he will sell them off for a big profit.
Just one but I refuse to spend untold thousands on junk that can cost untold thousands to make an attempt to even fix. None of them are worth the asking prices now. And for sure none of the old 14A's and under are worth what some are asking for them not even scrap price, to scrap cost plenty of $ now.
Say you get one of these and a final goes day one and turns that whole area into trash, cost to fix?
Even a good not in their 70's DIYer would not have fun, especially if the tooling is nonexistant, and then parts. Think before jumping on one, they can easily become very costly yard art, 30 years ago I dealt with the then much much newer than now, 46A's and a few 77V's that were pretty worn out and trashed.
The only time demand will pick up is when Cat starts building them again, but then they'd have to look like a Komatsu to be worth having, since the track frames dead axle etc, are not the best idea.
Say you get one of these and a final goes day one and turns that whole area into trash, cost to fix?
Even a good not in their 70's DIYer would not have fun, especially if the tooling is nonexistant, and then parts. Think before jumping on one, they can easily become very costly yard art, 30 years ago I dealt with the then much much newer than now, 46A's and a few 77V's that were pretty worn out and trashed.
The only time demand will pick up is when Cat starts building them again, but then they'd have to look like a Komatsu to be worth having, since the track frames dead axle etc, are not the best idea.
Just wanted to update that the D9H started thumping in the tranny while moving in gear and in neutral. I pulled the u-joint and magnetic screen. Plenty of metal sludge on the magnets (40hrs on previous cleaning). Input shaft a hard resistance spot from 1:00-4:00 when turning by hand.
I located a reman transmission from a shop close by that has been in storage 30 years, #4M4 for a 9G so hopefully some of the internals will be useful. Sorta excited to tear into it to see what’s going on inside.
I located a reman transmission from a shop close by that has been in storage 30 years, #4M4 for a 9G so hopefully some of the internals will be useful. Sorta excited to tear into it to see what’s going on inside.
You will be doing more than just the transmission.
There is the bevel gear/ bearings, torque converter, valving etc. maybe some got filtered ? They all share the same oil.
Keep us posted.
Oh and please share the $$ you know the prices for the machine the transmission and all the parts etc.
Would like to see how close my guesses are on this stuff.
Your time or not, labor is not free even DIY, hours to do it?
There is the bevel gear/ bearings, torque converter, valving etc. maybe some got filtered ? They all share the same oil.
Keep us posted.
Oh and please share the $$ you know the prices for the machine the transmission and all the parts etc.
Would like to see how close my guesses are on this stuff.
Your time or not, labor is not free even DIY, hours to do it?
The transmission is assembled and back in the dozer. Two planetary shafts, gears and the needle bearings on the #1 carrier was the knocking sound. Some of the race and roller bearings were also changed on the input shaft due to some rust and pitting. Inner race and roller bearing had started to separate.
Pinion and bevel bearings were good. Fine grit was in each valve so they’re all cleaned and re sealed. Next is cleaning the oil cooler, lines and draining the torque. I’m having trouble locating the oil drain bolts, that are behind the scavenge pump to drop the oil in the torque. Any other way to determine which two bolts? Drain is not stamped anywhere that I can see. Brake covers and backlash will be after.
Pinion and bevel bearings were good. Fine grit was in each valve so they’re all cleaned and re sealed. Next is cleaning the oil cooler, lines and draining the torque. I’m having trouble locating the oil drain bolts, that are behind the scavenge pump to drop the oil in the torque. Any other way to determine which two bolts? Drain is not stamped anywhere that I can see. Brake covers and backlash will be after.