D7-17A and pull scraper

Modern hydraulic scrapers or old CAT cable control models?

I would like the hydraulic model as my dozer doesn't have the CCU. But what cu. yd. would the D7 be able to manage?

I used 3T and 17A D-7's to pull a LeT. LS scraper that was 8 yards struck and 10-11 heaped. That was a good match and enough for them.

[attachment=18719]Dam pictures 2012 002.jpg[/attachment]There are so many variables of soil type, scraper design, haul distance etc, it would be hard to give you a concrete answer, but I would go with the 13 yard for sure. A 17A is going to have more traction/draft than most any rubber tired tractor less than 400 hp, so I think you could handle that easily. If you're going any distance, the extra payload is going to make a dramatic difference in how much dirt your get moved in a day.

When you're pulling a scraper, the width of the bit and how the bowl is made determines how hard it pulls and how effectively you can load it. If it has a "frost bit" in the center of the cutting edge, you can take cuts with that part only if the dirt is really hard or you don't have good traction. As an example of that, we have a small LaPlant-Choate 4 yard ejector pan which we pull with farm tractors. When the frost bit was long enough to use, we could pull it with a 4020 JD or do a really good job with a 5020, so 95 to 130 hp or so. It's old and the frost bit is worn so that it usually cuts with the whole 5 or so feet of bit at once and now it really works best with a 4955 MFWD about 225 hp.

Does your tractor have an auxillary hydraulic system or a CAT front mount hydraulic control? Just wondering if you have the number of valves and pressure capability you need.

In the cable versions, 13 cu. yd. is considered D8 size.

My dozer has the Cat front mount hydraulics, but the previous owner had put two fittings on one of the C-frame lift cylinders, I was going to put some quick connectors there. But you were wondering if I would have enough pressure to operate the scraper?