Dissenting Opinion by
Mr. Justice Cohen :I agree with the majority that the court below erred when it refused to read into the bond that language which was missing from the bond but was required by the statute. I can not agree, however, with the majority’s erroneous application of our unanimous decision last year in Commonwealth to use Walters Tire Service, Inc. v. National Union Fire Insurance Company, 434 Pa. 235, 252 A. 2d 593 (1969), which supposedly states the law on this subject. I also can not *291agree with, the majority when it states “[w]e simply do not believe that permanent repairs on a multi-use piece of contracting equipment fall within the coverage of the bond.”
First, these repairs were not permanent in any sense. Charles Davis, who had been an officer of C. Davis, Inc. in August, 1965, testified that an undercarriage had a life expectancy of 2000-2500 hours. William Fox, an employee of L. B. Smith, Inc., first testified that an undercarriage could be expected to last from 1000-2000 hours depending on the abrasiveness of the material against which it was operating and later testified that six months was a normal life expectancy. Davis testified that from May, 1966 it would have taken four to six months to complete the job. Therefore, the record supports the conclusion that in terms of the distinction enunciated in Philadelphia School District v. B. A. Schrages Co., 134 Pa. Superior Ct. 533, 4 A. 2d 558 (1939), aff’d per curiam, 336 Pa. 433, 9 A. 2d 900 (1939), these repairs were not aids or appliances which the contractor would take away with bim on the completion of the work but rather would (like the tires and related products in question in the National Union case) be consumed or used up in the prosecution of the work. The record indicates that the job could not have been completed without the services of such a large tractor and that this particular tractor was in such poor condition that it would not have been able to complete the job without these repairs. Under these circumstances any common sense definition of “prosecution of the work” would include these repairs.
Second, the fact that the tractor was used only 18 of 76 working days at the Wellsboro job is irrelevant to the question before us. As we stated in National Union, the test is not the actual use of the labor or material but rather whether appellant in good faith *292and reasonably (or a reasonable man) expected that the labor and material would be substantially used up on the job. Thus, we must look at the situation as of the dates the repairs were made (and not at later events) to determine whether recovery may be had under the bond.
While it is true that appellant did not deliver parts to the job site, that fact alone cannot bar recovery, see United States v. Dickstein, 157 F. Supp. 126 (D.N.C. 1957), because it would have been totally impractical to make the repairs to the tractor at the job site in the middle of winter. The only sensible thing was to bring the tractor to a garage and have the repairs performed there. Where the parts were delivered may have an effect as to the reasonable belief as to where they will be used (e.g., it may be more easily found that the supplier reasonably believed the goods would be used on the bonded job if they were delivered to the actual job site than if they were delivered somewhere else), but that is only one piece of evidence which must be considered with whatever else is brought out.
When the majority states that these are permanent repairs which do not fall within the coverage of the bond, they ignore the record. When the majority relies on the actual use to which the tractor was put, they are using the wrong test. Because National Union was filed after the trial in the court below, the record is not satisfactorily developed as to the application of the holding of that case to facts presently before us. I would vacate the judgment of the court below and remand the record for further proceedings and a determination consistent with the test this Court unanimously approved in National Union.
The majority’s opinion is manifestly unfair to the Bar of the Commonwealth. In April, 1969 we decided National Union and adopted the position previously *293taken by the Federal Courts. In June, 1970 we are faced with a similar problem, and the majority, while citing national Union and apparently approving it, ignores the test it enunciated. How is the practitioner to know what the law is?
I dissent.
Mr. Chief Justice Bell joins in this dissent.